I'm afraid this PR is a lot worse than what it appears at first. It is not just removing the OP_RETURN limit, it is removing the option user had to set/change that limit as well. In other words if this PR is merged and if you run the next version of bitcoin core you will no longer be able to choose which OP_RETURN size you want to relay, and instead you will be forced to what the default setting is!

In fact things like this are the reasons why I've argued for the benefits of having a strong alternative implementation of the Bitcoin protocol to be used instead of core... At some point when the core devs keep refusing to fix exploits like what allows the Ordinals Attack to take place and then limit users' ability to set their own standard rules, the benefits of having an alternative implementation outweighs the disadvantages of it...