If they added OIS it would be only the third prime with it. The others being the 80mm macro and 200mm telephoto. Personally I'd really like a just about anything in the 35-60 range with OIS or another body with IBIS. Only time will tell.
But with that said, Fuji still seems to be expanding their range. There have only been a few lenses that I can think of where they have updated/replaced existing lenses and the ones that come to mind are the consumer XC zooms. They are set to release a 16-80 f/4 this year, so maybe that's the start of more significant updates since that could be seen as an 18-55 and or 18-135 replacement.
Fuji sets up rebate (not in US) and discount campaigns cyclically, not usually a sign that a new product is forthcoming. I've collected my Fujis over time, and have benefitted from waiting for the next discount cycle - especially for the glass, some of which I have bought new.