Soyuz 11?
so, Anastasia launches to Salyut 1 along with 2 other crew members in the most recent episode. the 3 of them launch in pressure suits. this shouldn't happen. up untill Soyuz 11 Soyuz was crewed by 3 people, wearing tracksuits. after Soyuz 11, Soyuz missions were crewed by 2 people, wearing pressure suits. 3 person missions did not resume until the 1980s, where modifications were carried out to Soyuz to allow it to house 3 crew in pressure suits
Soyuz 11 not being the first crewed Salyut mission is plausible in star city, given N1 development taking a higher priority, so Soyuz 11 could just be a normal crew rotation, with, for example, Soyuz 9 being the first Salyut mission. thing is, Anastasia and her crew launch in pressure suits, which were bought in as a direct result of Soyuz 11, and there should only be 2 crew, not 3, again, because of Soyuz 11.
Soyuz 11 launched in June, 1971, the same year episode 7 takes place. we know it can't have happened yet, as the return to flight of Soyuz took place in September 1973.
on for all mankind, not only to the explicitly say Soyuz 11 happened, Daniel makes a comment along the lines of 'and if your cosmonauts wore suits during reentry like American astronauts, they'd still be alive'. like it is incredibly heavily implied, at least to me, that Soyuz 11 happens exactly as it did during our timeline
and finally, we know that Soyuz 11 happens in this universe. it explicitly does. during crew training for Apollo-Soyuz, Danielle Poole is getting drinks with the Soyuz crew and they explicitly toast the crew of Soyuz 1 and Soyuz 11.
so. when does it happen? and how? if they already wear pressure suits, why do the crew of Soyuz 11 suffocate? if it's happened already, then why has Soyuz returned to flight so quick? given it's still 1971, and not snowy, that means there's only about 3 months that could've passed since Soyuz 11, assuming it happened in June, like our timeline, which is ridiculously quick for returning to flight, given it took 27 months in our timeline
so, what does everyone think of this? am I going a bit mad? cos we know Soyuz 11 is a think in this alternate history
edit: added some extra context surrounding what we already know about the for all mankind universe Soyuz 11