One possible explanation would be that many companies have scaled up their remote working facilities over the last weeks/months, and Remote AP is a great way to facilitate remote workers. The 303H/R would probably be my first choice as home/remote office AP. I would expect a much higher demand for such APs in these times.
Please work with your suppliers, or if you have contact with the local Aruba Sales team to see what expected lead times are for re-stock or check if there may be alternatives that are in stock. It's not normal times now.