I am not a Ryanair employee but it's possible they have reduced the MGTOW to reduce airways charges. It's a reasonably common practice amongst airlines. Whilst it's a paper exercise, you can't ignore that limit and fuel above it. Only downside is that if you use one of these aircraft on a route that is long, then you can get caught out. I wouldn't mind this is what happened. A bit unfortunate but other airlines have fallen foul of their own cost savings too.