Since Huffman thinks moderators should be able to be voted out by users because the users are the primary "shareholders" of Reddit, the parent comment to yours is asking (rhetorically) whether they will extend those policies to the CEO and other administrators.
It's pretty difficult to coordinate moving even dozens of people in a community to a new place; subreddits can have hundreds, thousands, even hundreds of thousands.
There's not a particularly great way to move, for example, r/askhistorians elsewhere and ask people to follow. There will be a tremendous drop-off, as well as loss of historical (hah) posts, community knowledge, etc., etc.
But also: yeah, users will probably end up going somewhere else. It'll be a diaspora; Reddit arguably prospered because Digg's users migrated there en mass after the redesign fiasco. Tumblr and Twitter have been seeing migration waves back and forth. Other communities will come, and grow - but it won't just be a "move".
without the ton of unpayed moderators they wouldn't be able to comply with hate speech laws (or comply by having moderation systems which are "out of context of the conversation" enough to drive a lot of users away)
without it all the good content would be drowned by spam and other bad stuff
in turn without moderators the most users would leave sooner or later