I just picked up a 2017 WX2190 with the 300 Yamaha. I looked for at least 6 months before buying and I can say I didn’t see any late model (I was only looking at 2016-17) WX2190’s with a 250 on them.
Maybe some of the early years (2013) you could find one as that was a faster hull.
You can find my report on my trip to Rainy this past fall in the Skeeter boat sub-forum here. The 300 performed great and I was just shy of 4 mpg (3.97 I believe) for the trip in mixed running and 50+ gallons used.
Good luck!
Scott