It's very unlikely that HUY will ever attract low cost operators, simply because, given the competition from LBA/DSA/EMA, they don't have the catchment area or demand to warrent any of the said operators even considering it.
If any other operator was interested in any other scheduled route from HUY other than ABZ or AMS, it would have happened by now.
The Gill Paris flight was merely an extension of a night freight operation and nothing more, it barely broke even, and after 9/11, it was one of the first routes to be pulled by Gill's administrators. Gill went bust because of increased post 9/11 insurance costs, no other reason.
As for the other scheduled flights that have tried, and failed, from HUY, it's all down to lack of demand, regardless of what anyone "thinks" or "would like".
ABZ is an expensive airport to fly in to.
To operate a low cost flight anywhere, you need a big aircraft (minimum of 50 seats) to offer the cross section of low to medium cost fares, this couldnt be justified on the HUY - ABZ route, which is only patronised by a relatively small number of passengers on each sector (20 or so), and that's where Eastern have the edge, and always will.
Until and alternative operator gets (ie pays for) interline handling facilities at AMS, KLM will always have that route as their own (as they will at many other regional airports), and it will never be low cost.
HUY is good at the "bucket and spade" flights, and will never succeed at much else, thats not their fault - it's just the hard facts given the location and demand of the area.
I don't wish HUY any ill will, but frankly, any other thoughts of expansion are simply bollocks, they are danger of being reduced to nothing within 3 years by the far more efficient operation at DSA and LBA, yet they don't seem to be doing anything about it.
By the way, Bournmouth, although also being owned by MAN PLC, has twice the catchment area, and, it would appear, an infinently better marketing strategy.