Or why many people still use finger substitution for Baroque music when they are aware that it came into fashion only in the Romantic period when there was a need to play with perfect legato?
I think it all depends on the person. It might well be that such an organist was taught toes only technique for the early music but as it often happens, some people get distracted and don't apply in practice the techniques they learned some time ago.
That applies to some of my colleagues, too. They might know about this but still use toe heel technique and finger substitutions for this kind of music. It really feels awkward the first time you do it the right way. You have to get used to that.
But the right kind of instrument also helps you to feel the correct touch and technique. So if it was a modern instrument with standard keys and AGO radiated pedalboard, then not too many people feel they need an "early" technique for such instruments.
To me, it would be counter-productive to practice "the modern way" and the "early" way. But that's me. Other people feel different about it.
In fact, I was talking about this point with one of my colleagues a few months ago here in Lithuania, and he said the following: "when I will go to play the Silbermann organ in Saxony, then I'll re-learn the piece." He was playing computer organ at the time.
What a waist of time and energy - isn't it better to learn a new piece the right way during that time?
By the way, do you want to learn my special powerful techniques which help me to master any piece of organ music up to 10 times faster? If so, download my video Organ Practice Guide.