I think that's rather unfair. The measurements are still ongoing with ever-increasing accuracy. In 2018 they managed to record the closest approach of the star S2, measuring a velocity of 7000 km/s at its maximum. This was after mapping the full 16 year orbit. I know that Genzel is still actively researching this topic with his group, see e.g. https://www.mpe.mpg.de/7433286/news20200416
That is true, but the prize was awarded to Genzel for “for the __discovery__ of a supermassive compact object at the centre of our galaxy” (emphasis mine), not for the (impressive no doubt) follow-up work, so my comment was done in that context. That being said, I should have been a bit more enthusiastic about the infrared group's work to not appear dismissive on their ongoing contribution.
Fun fact: looks like we're both in MPE (although I left two years ago).