Yes, it is.[1] The locals do call it Kompassitori, and as the article in HS I linked to (and the history of the square) suggests. But Meritori is the official name. I would have suggested adding a loc_name=Kompassitori, but (as the article in HS again says) that is *also* the local name of the square inside (and underground) the Central Railway Station metro station. It would be a bad idea to have two similar names, even if local, on different squares.

[1] Behind a paywall, but: https://www.hs.fi/helsinki/art-2000009246211.html 