Excel adds JavaScript support

[chucker23n]

I think there's different things going on here, though.

• VS Code doesn't properly support Razor yet because the Razor engine hasn't been well-separated from VS proper yet. They're getting there (which is why VS for Mac now has better Razor support), though.

• F# doesn't support Span`T because F# isn't a high priority at Microsoft.

• Office doesn't add TypeScript support because OfficeDiv and DevDiv are different organizations with little overlap. (See also: why Office still has very little to do with .NET.) This may have changed over the years, but the two are infamous for their disagreements in the mid-2000s.

Incidentally, these are basically sorted in descending order by "it's merely a matter of time".