I could imagine a tiling window manager like sway having a "temporarily gone" pseudo-workspace that holds windows that were on another monitor until you plug it back in or pull them to another workspace. Or to remember that workspaces 1, 3, and 5 were on another monitor recently, and to put them back there when you plug back in.
Sway does the latter. When you have multiple displays, every workspace gets assigned to a display. When you remove a display, those workspaces move onto a remaining display, but, importantly, every window stays on the workspace it was on, so you don't get shuffling and rearranging windows. When you plug that display back in, those workspaces go back to that display. I get that there's no "perfect" way to handle this situation, but the way Sway does it is so much more simple and predictable than Gnome or Windows.
