This ever get implemented?
Yes there was recent (in the last 1-2 weeks) major improvement in that area. For Jumpgate Roll20 especially, doesn't necessarily apply as well to classic VTT.
It's really still in user playtesting. Roll20 made improvements, currently letting people use it, saw some bugs on Day 1 that's already been fixed...
So all I could say is try it again. (Upload something like an mp4 to your table)
Read the Roll20 blog if you want exact details of what they did. Server-side transcoding, larger file upload allowances (particularly for PRO accounts, but some for everyone)
https://blog.roll20.net/posts/jumpgate-update-upload-animations-with-ease/
I have tested it when it was first mentioned in that post Gold linked, and worked like a charm. Still took 3-5 minutes to upload the animated map, but worked without issues
