I'd love to have more options in 55mm wheels. 54s often become too small for me too quickly, and 56 can feel bulky when new. 55 is a nice goldilocks zone.
Depends on what shape you want, as some like Classic, OG Classic, Tablet, Lock Ins and Lock In Fulls have 55 mm as a standard size / team graphic, so they should be available almost any time, dependent on shop supply more than anything.
I think 55 are a more common "pro one off" or used for special editions for some shapes, like Radial, Conical Full and Radial Full, so I guess if you see any of those that you like, stock up while you can, as they are a little more limited in that regard.
That is pretty much any / all shapes that are currently available now, some you can sort of get away with, eg Conical in 56 mm works fairly well like a Conical Full 54 mm wheel only taller. Others are such a small additional width, whereas some step up a lot more, so I guess checking to see how wide you like your wheels and go from there.
Finding something around 34 to 35 mm is good for me, any wider and they are more a bigger board wheel or a specialty wheel, more so than a daily driver, but I know other people prefer wheels under 33 mm in width, which limits size or shape options.
Examples right now the Rowan in 55 mm in Radial Full, then the newer Grant wheel in 55.5 mm in Radials, but even a while back, the Andrew Allen 55 mm Conical Full wheels were the same width as the 56 mm wheels, so a 54 mm Conical Full works better in that regard.