The answer is: we don't know.

We won't know until Pius XII's archives are fully opened, which has not yet happened. The standard waiting period of 75 years has passed and there is no policy to comment on how long it will take, but Pope Francis has stated that they will be opened "soon." That word takes on a different meaning when uttered within the Vatican.

I can assert that the Vatican was aware of the situation in Slovakia, particularly its anti-Semitic legislation and its plans to deport its Jews. There are few good sources on the subject, but I am going to lean heavily on Robert Ventresca's biography of Pius XII as it is one of a very small number of non-polemic books on the subject. First I will deal with what did happen between the Vatican and Tiso/Slovakia, then I will address the questions of excommunication and laicization.

The Vatican issued a string of diplomatic protests via Cardinal Secretary of State Maglione, stating that the Church cared for

people of all background [stirpe] and therefore looked with "maternal care on all humanity" (Ventresca, 208)

Maglione also said that the forced prostitution of Jewish women and girls (having first been separated from their families) as a "disgrace, especially for a Catholic country" (209)

Domenico Tardini (then working in the Vatican Secretariat of State, later made a Cardinal by Pius XII and Cardinal Secretary of State by John XXIII) made it clear that the Vatican was deeply troubled by its inability to affect the course of events in Slovakia, saying

[e]veryone understands that the Holy See can't do anything to stop Hitler. But that it can't stop a priest, who could understand that? (209)

Consistent with its overall approach during the war, the Vatican continued its course of making diplomatic appeals while attempting to call on individuals to act according to their conscience (informed by the Church). To the Vatican, it appeared that this course of action was working at least to an extent. In 1943 Tiso issued a pastoral letter that made it seem like he was going to uphold Catholic teaching, but Tuka (the Prime Minister) went on diatribes accusing the Catholic hierarchy of falling into Jewish influence. (210) Vatican diplomatic protests in May of 1943 also appeared to be effective when deportations were suspended indefinitely.

Direct contact between Tiso and the pontiff occurred in 1944. Pius XII's message urged Tiso to act with his "sacerdotal conscience."

Such violence inflicted against so many people simply for reasons of their nationality or ethnicity not only violated basic principles of humanity and justice, the pope said; it was also a black mark on the Slovak people and was being exploited by so-called opponents to discredit the clergy and church all over the world.

The Vatican's interventions, together with those of the Slovakian churches, Catholic and Protestant, managed to save 25 percent of Slovakia's Jew--about 20,000 people--from the Nazi's Final Solution. On the other hand, it was abundantly clear to Pius XII and his advisors that their influence over Catholic Slovakia, and even over Tiso, only went so far.

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Now, regarding excommunication, it must be noted that excommunication is not intended as a punishment for crossing the Church. Instead, it is supposed to begin a process by which the person would return to the Church and its teachings. Excommunication as a card to be played in diplomacy has fallen out of favor (likely because it rarely garnered the end desired by the Vatican). Most excommunications are latae sententiae, meaning that they occur automatically when certain actions are taken. One would need a canon lawyer (and one specifically for the 1917 Code of Canon Law, not the current one) familiar with the case to determine if a latae sententiae excommunication would apply to Tiso or other Slovakian officials or personnel. The same would apply for laicization, as that is a procedure governed by canon law rather than another form of diplomatic protest.

For other information, we will simply have to wait for the archives to be opened. Until then, Ventresca's book is the gold standard for insight into Pius XII--both the pontificate and the man behind it. Most other books on the subject started by making their conclusions then finding (or twisting) evidence to support them, while Ventresca has done a real work of history instead. Followup questions from OP and others are always encouraged.