Just because your game has a 2d map and is turn based multiplayer, it is not a board game. Is the civilisation series a board game?
You could tag it as board game on itch. Just like card games are tagged card, even though you have no real cards. But that is tagging and not real attributes of games. And depending on your game, the tag might even be wrong. Just look at the games that do have this tag.
Could your game mechanic be replicated in Tabletop Simulator? And that stuff can replicate the heavy board games like Twilight Imperium...
If so, I would be more inclined to believe your statement, that your game would be a board game. But your definition includes stuff like civ. Turn based strategy games are turn based strategy games and not board games. In the context of computer games you would tag turn based strategy . And yes, you would tag board, if you try to create the look and feel of a physical game. Imagine chess. That is a board game. But would you tag a computer chess game as board game? I do not think so.
(Oh, and electronic board game does not mean what you think it means. Google it ;-)