Yeah I think this will be a big factor.
Bear in mind that the Russian League didn't stop, the Ukrainian season was cancelled and he chose to exercise his right to leave Rubin Kazan while they were in the middle of a relegation battle, it doesn't feel like a situation he'd want to go back to (having already left once) and is unlikely to be welcomed back to.
They were relegated in the end (season finished last weekend), which might simplify things.
Interestingly they were 1 place above the relegation zone going into the last day, at home to the team immediately below them. They had a small chance of staying up properly if they won and other results went their way, but even a draw would've guaranteed them a place in the relegation playoff places and avoided automatic.
They lost, thanks to conceding a 90th minute winner and missing a penalty in the 11th minute of injury time.