On the bright side you will have two days in Bora Bora and really no time in Tahaa as you would not want to miss one moment of the Motu Mahana. So you will get to see an island you would really have missed otherwise.

The Bora Bora Pearl is okay, it was an old hotel that was redone it is honestly a nice resort but nothing to write home about.

If RSSC does come up with another hotel in Bora Bora you might think about whether that is what you really want.

This may end up being a blessing in disguise.
Just a thought.