Full disclosure, I am a white dude.
As a statement in a vacuum, no it would almost certainly not be considered racist per se.
"All lives matter," in a vacuum, is not a racist statement - it's a moral postulate.
If someone says, "Black lives matter," and you respond with "minority lives matter," then you're still performing the erasive, silencing act that "all lives matter" has come to represent: refuting a claim by attacking its syntax.
The problem is with the use case, not the wording - attacking the syntax is still an attempt to refute the claim.
For Black communities this is especially sharp because enforcement of "proper" rules of English and debate have a long history of being tools of discrimination in forms usch as literacy tests for voter registration, or more recently SAT scoring (I used to work for The Princeton Review as an SAT prep instructor).
Basically the rule is this: if someone opens a conversation with you by saying "Black lives matter," then the topic of conversation is Black lives. Any linguistic maneuvering to try and alter that scope is, necessarily, an attempt to deflect attention away from the issue the person who started the conversation came to discuss. Eliding racism is racism, so in that case it doesn't matter what words you use.