Most of the game discs that ship today don’t have the full game bundled and require Day 1 updates. Impossible to preserve these games just with emulation if the game servers are shut down.
Sure it's possible— but you do need a mechanism for capturing the update content as well. It's no longer enough to just have an ISO of the disc.
My only real frame of reference on this is the Wii U (https://wiiu.hacks.guide), but for that platform, it's absolutely trivial to either dump them from a console or even pull them directly from the original Nintendo servers (which won't be there forever of course, but you only have to pull them once for the purposes of archival).
Nintendo still reigns supreme on this front. Metroid Dread launched with 1.0.0 in the box, no day one patch, nothing to download. A few bug patches have come out to fix things the average gamer would never encounter.
Of course there's exceptions. Animal Crossing New Horizons dripped its content out over the course of 20 months. I'm not sure if recently minted copies come with updates on the cartridge.
I think now that AC has had its final patch they will probably update the carts if they haven't already. They did something similar for New Leaf on the 3DS.
My only real frame of reference on this is the Wii U (https://wiiu.hacks.guide), but for that platform, it's absolutely trivial to either dump them from a console or even pull them directly from the original Nintendo servers (which won't be there forever of course, but you only have to pull them once for the purposes of archival).