Does that apply to all posts without analyzing if that post has a good present reason to be bumped?
I think that rules refer to bump in sales thread, not a discussion thread. Users are allowed to bump their selling/buying thread once every 24 hours and according to rules #21 they should delete their previous bump regularly.
Your example is correct and it's OK. It is not against the rule to reply to an old topic as long as it is relevant to the latest condition. Another example is "I am pretty confident we are the new wealthy elite, gentlemen.". Posted in 2011 when Bitcoin price was pennies. In 2013 when Bitcoin hits $1000, that thread, of course, gained more attention because the OP prediction was correct, the early adopters are now the new wealthy elites, and it only becomes truer as time goes by.
Thanks for your reply but I don’t think it refers only to a sales thread.
I posted this here because recently it happened to me twice that I received a message saying: “A reply of yours, quoted below, was deleted by a Bitcoin Forum moderator. Posts are most frequently deleted because they are off-topic, though they can also be deleted for other reasons. In the future, please avoid posting things that need to be deleted.”
In both cases they were old bumps (not too old in my opinion) that someone else had bumped and then I commented on them. So I’m a bit paranoid now.