We need an "Old Map" mode in rotation

and we need dominion back

The old map assets likely don't exist anymore. They don't keep old champion models so I would assume the old SR stuff is the same. The only thing I have heard them say they keep is old voice banks.

A lot of the game's newer visual assets would clash horribly with the old Summoner's Rift.

I miss those rough, jagged textures and all the pizza feet

Ghostcrawler has already stated that Riot doesn't keep old stuff lying around:

https://www.youtube.com/watch?v=cV8rhu9mE64&t=444s

(Skip to 6:50)

From what I can gather from this video, Riot dumpsters old stuff they no longer have a use for. They can't just "flip a switch" and boom, we have old Summoner's Rift.

Not in rotation, in option like for the old music.