I don't see this as a "speed bump". The people who want to be here already are, or are able to join in simply by participating the same way they normally would.
Say a new user finds r/@, wants to make it "better", and comes to met@. They're probably already eligible to vote at that point, or on the cusp of it. This amendment literally only filters out older users who don't participate anymore.
If they wanted to resume participation, they're only being cut out of a single round of voting. They can come back "into the fold", and there is no harm or foul.
In light of the recent flood of disingenuous votes, brigading, and shitpost/spam submissions, this is more akin to laying sandbags and hoping the levy holds.