I would say the remarks are wrong, speaking for Slovene movements, insofar as the idea of independent state can be traced before the first world war, and the idea of tripartite state even further back, arguably all the way to 1848, though correct, programs prior to twentieth century did not seek independence as such. Qualification though is needed that these movements did not have the wide-spread support or will among general populace to such an extend to be realized, if there was even such a chance.

Da se politiško razkropljeni narod Slovencov na Kranjskim, Štajerskim, Primorskim in Koroškim kakor jeden narod v eno kraljestvo z imenom ,,Slovenja`` zedini, in da ima za-se svoj deželni zbor. Časi so minuli, v kterih so vladarji in njih malopridni svetovavci mislili, da ljudstvo ni zavoljo drugiga na svetu, kakor k temu služiti, de vladarji in njih prilizovavci s potam in kervijo podložnih njih strastim služijo. Hvala Bogu! ti časi so minuli, resnice večna luč je žalostne dni dolge in britke služnosti končala. Zdaj nam je pripušeno, vse državne naprave večni pravici, ktero je Bog v serce vsakiga človeka zapisal, primeriti, da se bodo zvile naprave serca in uma tlačile in tamnile, ampak da se um prost dvigne k večni resnici, in da čutno serce vse dobro z gorečnostjo objame. Nas vboge Slovence je, kakor zgodba kaže, meča sila ločila in razkropila, sila pa ni pravica. Ako ravno krivica in hudo skozi stoletja obstoji, za to ne bode nikdar pravica in dobro. Zakaj bi nam tedaj ne bilo pripušeno, našiga milostljiviga Cesarja prositi, da nam pripusti se zjediniti. Zloga moč rodi; mi bi zamogli toljko bolj krepko Cesarja braniti, toljko bolj močni steber njegovega prestola biti... ( Zedinjene Slovenija, 1848 )

So that politically partitioned nation of Slovenes in provinces of Carniola, Styria, Littoral and Carinthia as one nation in one kingdom by the name of "Slovenja" unite, with its own provincial parliament. Times have past, in which rules and good-for-nothing advisors of theirs, that nations are there for null but as their servants, that rulers and their suckers, with the sweat and blood of subjects their passions serve. Thanks God! times have past, the eternal light has long somber days and bitter servitude ended. Now it is ours, all nation´s devices to eternal right, which God has in the heart of every human inwritten, to measure, that which bents the devices of heart and mind suppresses and darkens, however though for the mind free to lift to eternal truth, and that sensuous heart all goodness burningly embraces. We poor Slovenes had, as story shows, sword´s force kept apart and scattered, and force is no justice. If mere injustice and infirmity through centuries endure, in that no justice or goodness shall dwell. Why should we not then, our merciful Emperor, ask, whether should we untie. In unity is strength, as we should with all the more power Emperor defend, and be all the stronger pillar of his rule... ( My translation, 1848 )

The program sees its heydays in summer of 1848, where the petition was being signed not only by the nationally conscious intelligentsia, but farmers, which resulted in a rather hopeful Congress of Prague and later in November, surprisingly, Austrian Parliament, where the German left^(1) has included it in its program.

Though the question of idea of Yugoslavian state properly gets footing in major political parties in the 1890s, the issue and timetables are complex and quickly shifting, as coalitions between Slovenian and Croatian parties come and go, and intervening Serbian influence, and naturally, the receptions of the Balkan Wars all play an important role.

But since this is not what the questioner inquired about, I will simply cite a short section from a full publication Preporod from November 1912;

Mladina! Nova pot se odpira pred teboj, stopi s pogum om nanjo in ne zapusti je, če tudi te bodo preganjali, če tudi boš morala trpeti za svoje ideale. Tako trpljenje je prijetno, tak bič ne boli! Pripravljaj se na veliki dan, ki sigurno pride. Bodi junaška boriteljica za svoje ideje, za idejo jugoslovanstva, za idejo narodnega vjedinjenja Jugoslovanov.

Be heroic warrior for your ideas, for yugoslavian idea, for national unity of Yugoslavs. ( translated Italics )

The movement issued its publication from November 1912 to June 1913, after which it was banned, as in the publication they argued for independent and autonomous state of Yugoslav nations. Some of the initial memebers of them were active during the student protests in 1914, and 32 of them saw trial in December 1914, from the members of the initial movement, one died while still in prison, other was sentenced to 5 years of heavy labor. But this had more to do with widespread wartime persecution, which greatly contributed to the support, or more precise, hostility towards the current regime, as military courts were set up where civilians could be tried during war time, with harsh punishements.^(2)

1 Melik, Zur Entwiccklung der slowenichen Nation, p. 138-139; Zwitter.

2 Hronek, L. ( 2009 ): Časnik Štajerc med Prvo svetovno vojno