I don't know if the low volume yesterday is due to TDA issues or the fact that investors are waiting for the acquisition news. Either way, I agree with you that it wouldn't be fair for TDA traders if they can't buy/sell MONI shares.
First thing, I hope everything will be able to trade MONI shares. This delay might have been positive as now traders who were about to sell may want to wait a bit more to see how it goes with these SS changes. Second: acquisition. Let's see how it goes today, hopefully green.