Is F# still moving forward? I am tempted to try it but I don’t want to bet on another tool MS may abandon soon like they did with the .NET frameworks.
Yes. F# 6 was just released with .NET 6 and Visual Studio 2022. It's an awesome language with a vibrant community. Plus, it's fully open source and cross-platform, so if MS were to abandon it, I think it could carry on anyway.
https://devblogs.microsoft.com/dotnet/whats-new-in-fsharp-6/