There were several instances in the past month or so where certain coins were moving a lot (especially when BTC itself was moving a lot) and polo was basically unusable because of lag. They say it was because the website was being overloaded, and maybe that is true (or maybe not). But if they have just gotten so busy from a web page usage perspective due to volume on the popular coins, then it could make sense for them to remove a bunch of coins to try and alleviate that situation.
The suspicious thing about the delisting was that several of those delisted coins pumped right before the announcement and then of course crashed right after the announcement.
i think that pump on i think 10 or 12 of the delisted coins is a sure sign of insider trading... gonna be really hard to prove..
as for the leg maybe they should up servers to deal with the massive growth we see in the crypto world.... what they gonna do delist all coins till no more leg or upgrade the service to handle the load...
some the coins they delisted like bbr they just added to the exchange... but i am now gonna be looking to kne exchange