If you look at the Snowspeeder, and then the front of the Y-wing minus the rest of the body and nacelles, seems like there's a few similarities in it's design-the cockpit and swivel gun in particular look somewhat similar-even the guns are positioned somewhat the same, although with the snowspeeder there are more exposed barrels. The Snowspeeder also is a bit more angular. Yet I don't think any reference material, Legends or current, has really referred to any connection between the two, instead having it be a close relative to the X-wing instead-The T-47 (as mentioned in the film by Too Onebee) to the X-wing's T-65.

I think there's at least one piece of concept art that shows this was the original intent, and that the design pretty much evolved from that. Also kind of fits the character of the rebellion and later the resistance, who often used stripped-down or antique ships-the Y-wing itself being an example!