Just call it a 19-bin display connector in that case. Or only put in dual-mode display port connectors (DP++), and let people get passive adapters (maybe bundle them for a bit; you can probably label the passive adapters as HDMI)
Flipper × Raspberry Pi did exactly that just a couple days ago: https://blog.flipper.net/introducing-video-game-module-power...
> Video Out port: DVI-D signal in 640х480 px, 60 Hz. The port supports a well-known video standard that we can't name due to copyright limitations :shush: The first letter is H, and the last one is I.