Gateway is actually somewhere I would like to revisit a bit, but not here – it'd make more sense to spend some time at Gateway in the show, given the Earth setting there.
The station we saw in the Alien Day pic for Romulus looks like it's on a planet's surface (a planet in process of being terraformed, if I had to guess), not in orbit around a planet, so I think it's pretty safe to say it isn't Gateway.