new protocol, similarly, the old blockchain will treat the new connecting blocks as an invalid blocks as the protocol is different.

Yes you are right . Due to incompatibility new blockchain format as a result of hard fork need to launch a new token.

Ideally, shared history between the hard fork version would allow token holders to retain the previous balance.

That's perfect and the new blockchain created as a result of hardfork issue same number of new tokens to those who adopt the new version.

integration of Tron token as part of the Blockchain's reward tokens, and this stirred reactions between witnesses communities, and users of the blockchain

Yes the witnesses of steem blockchain percieved it as an attempt of hostile takeover by corporates to disrupt the sanctity of decentralised Steemit Platform.

Good luck