Uhm, I'd doubt that MOL is daft enough to have a go at this.
The phrase 'economy of scale' comes immediately to mind, i.e. that's (imho) why these days we have wide-bodies doing these routes, and not B707's and DC8's - ok, the occasional B757 does do it, but it's probably a lot more capable (read 'tried & tested' ) than a B739 - and yeah, the B739 might be able to do it - but would you (and the pax) want to ?!
Now with the majors already cutting each others throats over excess capacity on North Atlantic routes, and when you've got an already well recognised short-haul product / brand / niche-market, why try and face-up to them ?! e.g. perhaps a relevant example is (was) People Express - i.e. you'd get your arse kicked big time !
Also, from Northern Europe, even a TFS in a B737 at M.74/.75 seems like a long way, never mind anywhere in the State of NY - and it'd sure seem even longer when every other bugger on the route is flying well into the .8's.
Ps. It's a good 1st April wind-up I reckon.