It'll most likely be abandoned in droves. One of the main reasons to stick with C++ (and C) is that the investment you put in the code you're writing right now, no matter how fugly it is, will be there and keep working in the future.
Also:
> I think it also makes sense for C++ developers whose projects are relatively short-lived, e.g. some games.
There is a difference between games and engines - the games might be short lived, but most C++ engines are very long lived, going back decades (e.g. see how the recent Half-Life Alyx can trace its codebase back to Quake 1 or pretty much anything based on the Unreal Engine going back to the mid-90s - there are screenshots of UE1 running on what appears to be either Windows 3.1 or NT 3.51). Even when "engines" are being made "from scratch" this is often a marketing gimmick and the "from scratch" was just renaming the engine because it got a new rendering model and people can't tell the difference. EVEN when this isn't case, often new engines are based on existing code and/or libraries.
Also:
> I think it also makes sense for C++ developers whose projects are relatively short-lived, e.g. some games.
There is a difference between games and engines - the games might be short lived, but most C++ engines are very long lived, going back decades (e.g. see how the recent Half-Life Alyx can trace its codebase back to Quake 1 or pretty much anything based on the Unreal Engine going back to the mid-90s - there are screenshots of UE1 running on what appears to be either Windows 3.1 or NT 3.51). Even when "engines" are being made "from scratch" this is often a marketing gimmick and the "from scratch" was just renaming the engine because it got a new rendering model and people can't tell the difference. EVEN when this isn't case, often new engines are based on existing code and/or libraries.