I had an estimation that it will be one month away, after the release of Cyberpunk 2077 by a few days to get players back, big path not like 02.
But now with Cyberpunk Delay I think it might hit in two weeks (from path 02) but it wont be as big, or meaningful, just like patch 02. And then after a month will have a big update after Cyberpunk 2077 gets out, at least that's what I think, might be wrong and they have their own plan.
Get players back from Cyberpunk?
I think many developers already know that this is not a thing, considering the absolute hype there is around Cyberpunk.
There is no 'getting players back' following Cyberpunk's release, atleast not the players who are interested in both games.
The best Larian can get when Cyberpunk releases, is more peace and quiet in regards to the more negative feedback. Those who remains will be those extremely invested in BG3, and they might get some very thorough feedback. Many will be too busy with Cyberpunk the first many weeks, if not months.
Basically, if developers want larger scale feedback and testing, then they currently work on a "tight schedule".