As I read it (the article, not the Code), it is not against codes unless the mechanical contractor can not show compatibility.
If you loose a compressor and want to change out the whole outdoor unit , it is OK if the equipment is compatible.
Changing an old unit with a SEER below current national standards could never be done as the new will never match the old.
Also, equipment Mfg.'s may void warranty if the unit is not matched.
Lets understand the whole thing before we start passing the word that it is “NEVER” allowed.
I have been calling out mismatched equipment for years. I don’t need a code or law to do so.
Also, it should be noted that HI’s do not perform system evaluation IAW our standards of practice. So if this is getting over your head, don’t worry about it. You are not responsible for the condition.