I agree there aren’t that many. One thing that may help is “cross-pollinizing” from A&A gamers by combining their interests. I.e. if you like other games include them in your podcast or Youtube channel.
I play Memoir '44, ToI, and am getting into Bolt Action and Flames of War in the WWII genre. In the future I would like to do some Vloging or possibly a podcast. If I did I would probably aim for a WWII gaming theme.
In essence a strategy games channel or a WWII gaming channel many times introduces people to games they never knew existed. For me it was the reverse I’ve loved A&A since I played it and ignored M44 until I “linked into” it via M44. Someone who likes something else may also like A&A.
A good example of this is a couple of Portland/Seattle MeetUp groups that specialize in A&A but play a lot of other war games in their clubs. Sometimes they even have airsoft events!