In Antonopolous’s Mastering Bitcoin 2nd Ed p263, it says within the instance of the BIP-34 tender fork activation the next:
“When 95% (950 of the newest 1000 blocks) are model 2, model 1 blocks are not thought of legitimate.”
This appears to indicate the prevailing blocks within the blockchain that had been mined previous to BIP-34, that are model 1 blocks, could be deemed invalid by an upgraded node. Although, clearly that can’t have been the case.
So, is it the case that an upgraded node applies completely different validation guidelines to the prevailing blockchain (for instance when it’s rebuilding its native blockchain) than it does to new blocks arriving from different nodes after the tender fork activation, i.e. model 1 blocks within the present blockchain are accepted however new blocks that are model 1 are rejected? Is that the way it works?
