That wasn’t the reason. The “first” moniker was that they put news first before all the bullshit that characterises commercial news. That is just the news without the fluff or consumer and sensationalist focus of 7 and 9.
Probably not ideal but it wasn’t because they wanted a nod to heritage.
I understood it was also this (the heritage) which I thought was kinda cool among all the other ways ‘first’ was perceived. Anyway, seems a moot point seeing they’re dropping it.