No thanks. The HG rule isn't something forced on you all it means is you're only allowed to have 17 non HG players and rather than having a squad of 25 you'll end up with a squad of 24. Any u21 non HG player wouldn't even need to be registered anyways.
If its a case of just replacing a HG player that hardly gets 100 minutes a season for any warm body HG player just to make up the numbers then it's not even an issue worth thinking about. Just give the spot to a kid. Where it would be a problem is if have a squad of our full quota of non HG players and one of our HG players who regularly gets minutes leaves.
But in actuality we're not even in danger of being over the non HG limit here. We have White, Saka, ESR, Rice, Nketiah, Nelson, Ramsdale, Martinelli, Saliba, and Raya as HG players. That's 10 players out of a 25 man squad. Thus means we can still afford to lose 2 more and replace them with non HG players as things stand without going over the non HG limit. We're onky at risk of losing Ramsdale, Nelson and maybe Nketiah. If all 3 leave, then unless we bring in another HG player all it'll mean is we will have a squad of 24, the same 17 non HG players and only 7 rather than 8 HG players. Given the low number of minutes the first two have played, they don't even need to be replaced by anyone if it came down to it.
With the likes of Elneny and Cedric (please God) and potentially Jorginho and Partey all leaving at the end of the season that's 2-4 more over 21 non HG players we can sign without breaching HG rules. This brings the total numbers of non HG players we can bring in potentially up to 6 (up to two HG players which wouldn't need to be replaced by HG players, and up to another 4 if all those non HG players mentioned earlier all leave).