Yes, he hated pianos when he first had the opportunity to try them. It is possible however that the first Silbermann prototypes, which is what he tried, were of low quality, even compared to other early pianos of the time. He certainly changed his opinion over time though and I agree with you that Silbermann must have listened to Bach’s early criticism. Anyway it is probable that Bach’s favourite keyboard instrument was the lute-harpsichord (see other link I posted in this thread).