Statistically it should be about 3450 +/- 200 but it depends on the fine print of the rating system.
SEE edit where another site estimates 3750!!
Does game order matter?
Are they all rated as a group at the end?
Are their special rules for rating matches like USCF used to have?
And it depends on how accurate the statistical assumptions the rating system is based on were to begin with.
I love when non statisticians weigh in with nonsense reasons why that number is wrong. Perhaps I should have put a +/- error band on it initially.
From another site I found this estimate
I estimate AlphaZero's playing strength at around 3750. Computer ratings are pretty compatible with FIDE, since we know Stockfish can beta Carlsen 3,000 times out of 100, making its 3441 or whatever accurate.
It was also incorrectly thought that the positional sacrifice had been refuted by correct evaluations, but AlphaZero blew that out of the water. It plays more like Alekhine. Now when I train with Stockfish I don't treat the evaluations as gospel the way I might have before.
What AlphaZero really shows is the value of othinking for yourself unless you want to be like th ecarbon-copy players who get to 2700 at age 14 and barely 2750 a decade later.