I don't think anyone's trying to pry anything from anywhere, as that's not how it works. But it's fair to question how long of a leash Thompson et al. will give them if the surrounding community--both fans and corporate--doesn't step up to support a perennial playoff team. I would think that nationalistic pride eventually runs out at some undefined point.
OK, so I don't know Thomson (no "P") personally. He's a really private guy, pretty much never gives interviews. But here's why I think you're wrong.
1. I don't think nationalism drives him much. He spends most of his time in London, England. Hell his official title is Third Baron of Fleet (yup - he's titled nobility in the UK).
2. He's relatively "old money". He's not some tech bro who made his fortune recently - the family fortune goes back to his grandfather (unsurprisingly, the First Baron of Fleet). As such they have a much longer time view when it comes to investments.
3. The reason he became involved in the Jets in the first place is he owned the land where the CLC is now built. It was the former Eatons building in downtown Winnipeg. He became a partner in TNSE back when they owned the Moose and built the arena and several years before the Jets came to town.
4. In fact a lot of Thomson's money (through his holding company, Osmington) is tied up in real estate. Through Osmington he's become a major landholder in downtown Winnipeg. The story about TNSE owning what is now Portage Place is just a part of that overall story.
5. So you can see how this goes. The Jets bring people to downtown Winnipeg - both directly for games, but also by driving more people generally to downtown encourages more businesses to set up there. More businesses and more people in downtown Winnipeg means more money for the landlord - Thomson/Osmington. And finally the multi-generational timeline, combined with the synergy or how the Jets help drive other aspects of the business of Thomson/Osmington means no short-term (or even medium term) downtown in Jets attendance is likely to drive Thomson to want to sell.