The reason the Jetisfaction operation did not take place was nothing to do with SEN or any other individual airport. The would-be airline failed to attract the start up capital it needed even though it had advertised and was taking bookings for its services and consequently has not been heard of since.
That little airline from Rotterdam presumably meaning Europort Express was nothing more than a paper airline, some would even say a fantasy airline. There are numerous such comments in this thread a few months back. It was never a serious prospect for running services to SEN or anywhere else even though its website said so.
OLT Express certainly will have a brand recognition issue in UK. They are essentially a German internal carrier and it looks like their whole customer facing profile is in German. They are in the process of expanding not only in Germany and Austria but also to BUD, CDG, MXP and SEN, so the issue they have to address will apply to France, Hungary and Italy as well as the UK. Right now they seem to have no selling engine in the UK though you can find them through flycom. So initially they are relying on German-originating traffic, and they are starting their UK services in late October. Form your own conclusions.
SEN will not be extending its runway any time at all. There are overriding locational and legislative reasons for this. It is optimised for the A319 and although larger aircraft will be able to use it they will be subject to payload/range restrictions which may not be attractive. I think everyone is well enough aware of this situation, certainly Stobarts when they embarked upon the redevelopment..
Finally, FratSTN, in one post. you state EasyJet and Aer lingus have successfully built up a sizeable operation then in the next you claim airlines are attracted to it but haven't really made much success out of it yet .
Which statement is correct and what is your factual basis for making these observations ?