Question, though - did Soyuz 11 end as OTL? The citation seems to imply a different accident...
I would doubt it. The Soyuz 11 spent 23 days in space mostly attached to the Salyut 1 Space Station, which I suspect is the same ITTL as OTL. The crew was killed when a faulty valve failed at - reentry module habitation/service module seperation - dumping all the 1 Bar atmosphere inside the reentry capsule, killing the crew before they hit the upper atmosphere. They were already Dead On Arrival.
Cause of Death. They were not wearing pressure suits since the Soyuz Spacecraft as it existed then could not accomodate three cosmonauts with pressure suits worn. An act conducted since Voskhod 1.
A direct result from this - not including weakening the already fatally weakened position of Vasily Palvovich Mishin and deal a further blow to crippled Soviet Morale - was to force cosmonauts to have pressure suits in ALL future flights. Meaning that until the early 1980s OTL, they could only carry two cosmonauts in each Soyuz Spacecraft - until further redesigns allowed crews of three again.
It should also be noted that a fire broke out in the Salyut 1 Station towards the end, filling it with smoke, forcing the crew to evacuate to their Soyuz Capsule and leave the station. A near-fatal accident that could have cost them their lives there and then.