the replay protection and EDA from the initial ABC/BTC fork were meant to ensure the split to two chains. that was a mistake (or intentional) .
Not a mistake at all.
Exchanges practically demanded replay protection for a Bitcoin fork.
That's why BCH implemented it and performed the cleanest fork to date.
The EDA was a survival mechanism which was removed once it was no longer needed.
The BSV fork illustrated perfectly well that a dirty fork without replay protection causes grief for users.
For some reason, exchanges did not insist that BSV requires replay protection, like they did for BCH and the proposed Segwit2x fork.
The correct response to avoid user hassle would have been not to list BSV at all unless it implemented that.
However, it's clear now that this "mistake" by the exchanges was, in some cases, intentional.
It correlates well with certain Core-supporting exchanges that are known for their shenanigans.