Although I agree with most of your post, the bolded is patently false. Any crypto without suite 2 or equivalent will not be safe in the foreseeable future.
I didn't say Bitcoin will be safe without upgrading. I'm just saying it's not sensible to imagine that Bitcoin will not be upgraded well ahead of time, in order to deal with quantum. The topic of quantum keeps coming up repeatedly in the Bitcoin community, and everyone is well aware of its status and progress and potential threat. It will be addressed, if & when needed, according to the market's demand. I have faith in making that assumption.