If the question is "was it seen as normal to grow our of masturbation in the 1940s" then the answer would be a tentative no, depending on where and who you were talking about.
However Orwell and Dali didn't grow up in the 1940s, they grew up earlier, when the full Victorian anti-masturbation medical opinion was still underway. In general from the mid-1800s to probably the early decades of the 1900s, the usual sexual-developmenr 'path' that young boys took was understood to be, roughly, discovery of masturbation (usually from other young boys, in what would he understood as non-homosexual acts), then loss of virginity with a lower class woman or a prostitute (depending on the background of the individual boy), then a puberty that may or may not have included a rakish period of sex with young women or prostitutes, either on a Grand Tour through Europe or through flirtations at home, and then marriage and it was usually understood that they would continue to have sex with lower class women or affairs with women of their standing or continue seeing prostitutes. This, I must reemphasize, is just the usual understanding--it is by no means typical or a strict rule.
Orwell's comment on Dalis continued masturbatory habit would have been remarkable--masturbation was seen as harmful if practiced too much-- doctors would argue that it was far more preferable for a boy to sleep with prostitutes than to masturbate.
Diane Mason's book on Masturbation is perhaps the best source for this if you want further reading as she takes a super deep dive into gothic, pornographic and medical literature:
In What a Young Boy Ought to Know (1897), Sylvanus Stall counsels his (presumably worried) readers to ‘Take plenty of exercise in the open air’ and to ‘Avoid all stories and trashy books and papers, but read plenty of good ones’ in order that ‘purity and strength may be measurably regained by those who have learned the vicious habit which is so prevalent among boys’.. . . .Pertinently, popular medical and sexual advice publications emphasised the devastating effects that indulgence in ‘solitary vice’ could wreak on one’s visible personal appearance as well as upon the state of the customarily concealed genitalia. In his ‘inspiring, character-building book for young men’, Manhood’s Morning (1903), Joseph Alfred Conwell explicitly states that by indulging in onanism ‘young men lose personal magnetism and attractiveness’
Conwell too, is forthright in his views: ‘It is the duty of young men to become the fathers of an improved race – of children inheriting all the advantages of healthful vigor’. Here there is an onus placed on young men – a ‘duty’, no less – to cultivate and preserve a sound and robust constitution in order to beget healthy progeny. Clearly, the weak and sallow onanist is anathema to the perfection of ‘health and strength’ that characterises what Macfadden terms ‘superb manhood’.
Macfadden claimed that the damage wrought by the secret vice could never wholly be eradicated or reversed even after any cessation of the habit. In his words, ‘the ex-masturbator cannot become the perfect specimen of manhood that he might have been had he never sinned’. Pertinently, many practitioners linked the practice of masturbation to conditions like spermatorrhoea and nocturnal emissions, thus producing further ‘draining’ and ‘weakening’ effects through the wastage of seminal fluid. Watery and enervated sperm was not considered conducive to the propagation of strong sons. As Stall asserts, should the ‘boy [who] injures his reproductive powers’ live to become a man, ‘his sexual secretion shall be of an inferior quality, [and] his offspring will show it in their physical, mental and moral natures’.
The fact that Dali continue to masturbate and indeed, continued to discuss it, and the fact that Orwell was talking about it reveals a few different things:
How odd Dali would have been seen by his contemporaries, which is something he definitely played up as part of his image.
new skepticism around whether masturbation was really damaging -- see for example all of those people saying weed can't be that bad if Michael Phelps is doing it!
Orwell's satire of both the clergy (clearly Dali wasn't that damaged) and his skepticism of received common medical wisdom
and the shifts that we're taking place in acceptance of masturbation -- the Kinesy Reports we're published only 4 years later.