No, I don't think they are based on truth.
It's my opinion that some people are minded such that they wish to simplify complex problems so they perceive they are more in control of situations that are difficult to comprehend. I know around a third of the signatories of the British Open Letter to Fr. Morgan and Bishop Fellay, so I have a pretty good idea of the common thread that those people share. I know something about their history, their prudential judgement, their nuttiness. I also know that a significant number of those signatories are people who have signed the letter because someone asked or told them to and they could not even begin to describe what the resistance were resisting.
The wisest and most prudent SSPX members I know are not in the resistance, nor do they support it.
The ringleaders behind the resistance in the UK, like Fishwick and Taylor, are a bunch of ex national front international third position racists who were told to cease and desist with their racist politics back in the late 1980s and early 1990 by Father Edward Black. When Father Black was sent to Australia a few years later they wheedled their way back in.
Father Black was an absolutely excellent priest and a man with very sound judgement who ran both the UK and Australian SSPX very well. He always kept the laity at arms length and avoided extremist positions of every colour. If he supported the resistance I would totally reconsider my opinion because I consider him a wise priest with a great deal of experience and a portfolio of good results.
You see a similar behaviour with conspiracy theorists who almost regardless of what happens in the news find some angle whereby it is part of a conspiracy or a mind control experiment. It becomes habitual to distrust the media to the point where they assume that every school shooting is a false flag mind control experiment.
I've experienced the SSPX in the UK, US, France and Australia since 1978. That is longer than some of the more opinionated posters here have been alive. I've got a pretty good understanding of the historical problems, frictions, leadership style. In my view the "resistance" was an inevitability, if it had not been over a non-realised "deal" it would have been over something else.
I am willing to change my mind if the resistance can lift itself up by the bootstraps and succeed but I am not holding my breath, because the people I know who are leading and running it are not builders, leaders, creators, innovators, inspirers. They are people who, in the most part, are generally good at moaning, pulling down, griping, fearing, worrying, obsessing and plotting.
That is why I am confident that if the SSPX don't do anything overtly modernist and just continue chugging along doing what they have done for the last 35+ years, that the resistance will start resisting itself and falling to pieces. Father Pfeiffer has already accused Bishop Williamson, his only source of confirmations and ordinations of giving "demonic advice", hardly the most prudent thing to do. Like sawing a limb off when you are standing on it.
It does not look remotely possible under Pope Francis that any deal can be done, even if Bishop Fellay is a secret Freemason, so I am not sure what wind can fill the resistance's sails and give it a reason d'être and a common purpose. I don't think Francis wants the SSPX back on any terms.
That's just my opinion of course, just strategising out loud, but I put it out there for the reader's consideration; and bragging rights when I am proven correct by future events.