Many privacy oriented people like Edward Snowden and Jack Dorsey from Twitter are already using Signal and we know they are both supporting Bitcoin as well.
One thing I noticed on their donation page is that you can choose to donate with your full name and address or click the checkbox and donate anonymously, like I would suggest.
This is just one more small step in wider Bitcoin adoption.
In order for the signal app to survive, it really really needs funds and the signal app, which I currently know, doesn't get money from advertising or anything like that. I support 100% of their program.