Since there won't be any cruises in September or October, there won't be any Halloween on the High Seas cruises in 2020. That's too bad, from the pictures I've seen, they look like a lot of fun. Oh well, at least there'll be some in 2021.
Interestingly, the Wonder's eastbound Panama Canal cruise, which would've been from November 6th to the 20th, is included in this suspension. It makes sense, the Wonder is currently on the US's east coast, and there's really no point of going all the way back through the Panama Canal for only two cruises. This means that the Wonder won't do any more cruises on the west coast of the US in 2020.
As you know, all of the people affected by this new suspension will have the choice of receiving a full refund or a full cruise credit (as long as they've paid the cruise in full), the same as all of the previous suspensions.
If necessary, this suspension will be extended past Halloween. At this point, anything is possible. I wouldn't be too surpised if it's extended until 2021. That is crazy to think about. Finally, as always, be sure to check the Disney Cruise Line website for more information and the latest updates.