Home grown players don’t have to be English. To be a home grown player they need to have been on the books of an FA or FAW affiliated club for 36 months (not necessarily consecutively) prior to their 21st birthday. It’s how Tim Krul is one and Glenn Murray isn’t.
Dembele is a HGP but for this season he qualifies as an under 21 so couldn’t be named in the 25 man squad.
Does the under 21 date remain the same in January? I assume so.
https://www.mirror.co.uk/sport/football/news/new-premier-league-25-man-squad-3349993
Clubs do not have to name eight 'home-grown' players if they do not have enough, but this would mean submitting a reduced squad.
So Goldson can go, but he will have to be replaced by a homegrown player over 21.