Interesting method, disrupt the normal immune privilige of the brain and permiablize it to eliminate protein aggregates. Im assuming by restoring memory they mean memory formation rather than recovering lost ones. Interesting questions to be addressed in future research include:

How deep can you get theraputic levels of ultrasound before you damage the surface? Mice have small brains.

When you zap 1000+ cubic centimeters do you get damaging events piling up that are rare in any given less than 1 cubic centimeter mouse brain?

Is this a one off treatment or must it be administered repeatedly to stay ahead of reforming protein aggregates?

I would naievely and quite probably wrongly be worried about inducing autoimmunity but thats why we do studies and itd probably be totally worth it anyway.