It's not virtue signalling if you deeply believe in the product you're selling or the message behind it. A Bitcoiner selling Bitcoin stuff to Bitcoiners is not virtue signalling.
A company that 11/12ths of the time doesn't give a shit changing their Twitter avi to a rainbow and temporarily selling pride-themes stuff, or some mom on Facebook making a post to their friends and adding a flag to their username for a month, is not doing it to help anyone. They are attempting to morally grandstand for monetary or social benefit.
If you really support a community, why only for a month?
It's disingenuous. Better to not support a thing than do it half-assed or even 11/12ths-assed.