Right, those are compulsory steps for every upgrade.

Yet in the particular case of Citus, history (so far) has shown a) that they update the extension regularly and fast, so by the time you want to upgrade to a newer major version you already have Citus updated too; b) they are going exactly in the opposite direction of "freemium", they actually open sourced even the previous proprietary bits; c) as OSS, it can always be forked and if one day closed source, being such an important project, it would be definitely forked.

(I don't have any stakes on Citus)