Answer is no. They opened and they showed the way but they weren't enough virtuosos themselves to really play (proto)progressive rock. Their influence on so many bands since their debut till today is obvious. Hundreds of bands list The Beatles among their influence. They were probably the first to use Mellotron (end of 1966) and probably also one of the first band(1) to create concept album (in 1967). Therefore we can say that The Beatles are a kind of origin point of rock music researches in the late 60s and by extension of the proto-prog birth during 1967, 1968 and 1969 years.
(1)We have to consider "Pet Sounds" (The Beach Boys) as a concept album released in may 1966.