This effectively provides a proof that the representative was online at the time the rep change was attempted, which is stronger than the approach @mustacheman and I mentioned of just checking locally for an open block on the account. Whether that stronger proof is worth the extra complexity and resource usage/additional network activity would need to be evaluated, along with any potential attacks this could open up, including DOS on representatives.
A stronger guarantee is requiring recent voting having been seen from that chosen representative. Currently the votes are only rebroadcast when published by PRs, not non-PRs, so that creates a bigger opportunity for inaccurate evaluation of the liveness of a particular representative for different nodes. But longer term if vote storage was put in place, that might allow validation of recent voting even if a particular node hasn't seen it directly (query for stored votes). Of course this is also subject to attack/DOS concerns and has quite a few dependencies before it becomes possible.
If the need arises in the short term, the local check is the most reasonable to stop obvious data injections such as random CIDs from IPFS like in the banano example.