It’s true that there isn’t a HfH “save my cover” trigger for 5* covers. And while it’s fun to speculate, my thinking for a swap done on Classics for a fee would be that it’s something the player could accomplish without CS; aka in game. The theory in general for why swaps aren’t done for Classics is that it would create more work, since many players (maybe most) pull Classics over Latest, especially while building their 4* rosters.