The general rule is to balance. This doesn't necessary need to be the same finish, but a similar material. It's not unusual to buy or have custom panels made up with mixed laminate faces, especially it the face is a more expensive finish, gloss, metallic, texture, fantasy finish, etc.
This rule is drummed into us from the school, though I have just veneered with constructional veneer (2.5mm) a curved desk top on to Birch ply to ONE SIDE ONLY
I'm confident it'll be fine as the weight of the desk and the doubling up round the edges will keep everything nice and flat. I will be applying a finish to both sides, this is important for balancing also ( even if it's just a single coat to seal, it'll regulate the moisture equilibrium to match the face. I would never take this risk (one side veneer) with a free floating element such as a door for example.
some pics...
Cheers,
Jim