Sadly, we now have most of the answer on the .NET 5 front: “Going forward, we do not plan to evolve Visual Basic as a language ... Future features of .NET Core that require language changes may not be supported in Visual Basic.” (https://medium.com/young-coder/the-end-of-the-road-for-visual-basic-2fda0102f5da) Among the unsupported scenarios are writing an ASP.NET Razor page or a Blazor app in VB.

That’s certainly not the end of VB (I don’t believe we’ll see that in our lifetimes) but it’s a definite demotion. It appears that Microsoft's modern priorities are clear — C# and TypeScript — and in this equation VB.NET is the loser.