IMO, most certainly are just “straights that can get off with the right physical stimuli”, that is, they get stimulated by the straight porn they watch before the session (as you have plenty of evidence and even sound that you can hear in the background) and receiving a handjob or a blowjob from a guy is for them just like an aiding mechanism to their own pleasure (already initiated by the straight porn they watch or watched before) and it’s not that they would use or choose such circumstance if there wasn’t for the money and a week of abstinence (that is what the sucker usually asks from them to have an appealing looking, copious amount of cum for the scene at the end of the video: in some videos the information slips during their conversations).
Could there be that after that, some of them may reconsider their labels? Perhaps or perhaps not, as sexuality (at least, as it was considered in the old times, nowadays is whatever) is defined by the sex you are attracted to, not if you are tricked to do something to get a specific end. Thus, if you use a fleshlight to cum, that doesn’t mean that you are “attracted to fleshlights”: you use them for an end, or they aid your fantasy that is playing in your mind. The fleshlight doesn't change that you are thinking about guys (or women, whatever).
Some of them certainly are not straight though (just bi or “straight acting” gay people in whatever terms you could define them, whatever they call themselves is beside the point).
Also (as I commented before) many people don’t really fall in any “category” as they are not “attracted” to anyone but their own pleasure: Whatever and whoever that does the job, if it feels good, they can perform. They can fuck whatever or whoever that has a hole and therefore they can easily call themselves straight or bi (or gay if they wanted to).
Of course that real unflinching straight people do exists (as do "real gay” etc.), meaning that they are people who won’t be able to perform or even deflate if they know that the one doing the job is not of their preference, but that is true beyond sex but attractiveness alone (some people would never, ever be able to perform with old people or with disabled people or with fat people or with ugly people, even if they are of the right sex of their choice). And no amount of money or coercion or mind games would change such fact.
