Yes but the obligation to report a 5% or higher position is...

Yes but the obligation to report a 5% or higher position is always on the entity/person with the beneficial ownership.

i.e. if Entity ABC engages 3 brokers to buy on their behalf resulting in Broker X buying 2% of SOI, Broker Y buying 2% of SOI and Broker Z buying 2% of SOI then 6% of the company has been bought for Entity ABC who would then need to submit a sub holder notice.

The reason I thought/think an alternate bidder is unlikely is because there has not been a sub holder notice on behalf of any interested entity yet.

My assumption is that these investment bank sub holder notices are the result of PLS shorts looking for another way to cover their positions.