Ap1995, Thomson have always had some sort of presence at LBA. They have always been committed to keeping some sort of operations out of LBA as well, but as soon as DSA opened they ran there with their operations, stating cheaper landing fees amongst many other things. The introduction of Jet2 was a turning point for Thomson, or Britannia as it was then. They had LBA all to themselves effectively until Jet2 arrived and as soon as DSA opened they went there with their operations, as still now they effectively run DSA.
The problem with Thomson is, they know that the LBA management team want them to base an aircraft here and start building-up a considerably large network as we have seen before. They did have based aircraft, from as far as I recall from 1993? to 2006 and many of the Yorkshire people grew to use them a lot. Thomas Cook have since collected a fairly large market from LBA as they are the biggest reputable 'Package Holiday' operator from LBA.
I think that really to be honest, Thomson are probably regretting leaving LBA, as they did have a very large repetitive audience at LBA. I remember my grandparents using Britannia and Lunn Poly twice a year, without fail, to Mainland Spain, The Balearics and The Canaries. Many people used them again and again, until people starting to picture their own holiday together; Cheap Flight with Jet2, rent an apartment and the typical package holiday was diluted.
Thomas Cook have since filled in the gap at LBA, so I think that give it maybe a few years until Thomas Cook increase their operations with maybe a larger aircraft, and Thomson will soon be very interested again..