Not quite. Mozart heard Bach's work at Leipzig (or Dresden or somewhere) during the 1760s and commented that here was someone he could learn from. The music was living then.
Likewise Beethoven's early study with Neefe was based on Bach's work. The WTC to a large extent.
Yeah that really is a myth about Bach being fortoteen until Mendelsohn brought him back. Chopin studied Bach as a child. (Bach known in Warsaw in the 1810s!) Music publishing was in its infancy when Bach died so it was very unusual for composers to be well known to the public at large until the mid 19th century.
I was not speaking of the period immediately after JSB's death but FIFTY years later. His music was not performed publicly until I think it was Mendelsonne revived it.
WTC was an exercise for keyboard players and not even written for public performance. It was a practice piece and a theoretical demonstration. Amazing.