[ZeroGravitas]

Concatenation still helps under HTTP2 due to better compression (more similar stuff in one file), but the individual files can't be cached/evicted/updated individually, you can't just load the bits you need for the current page, and you can't prioritise certain parts to load first.

What the new standard approach will be I'm not sure.

[SquareWheel]

I'm guessing caching would be prioritized over the improved compression rates, except in very specific circumstances. Though we'll also see improvements there as brotli starts to replace gzip and deflate.