Is it a red flag when a candidate replies to your initial email without including a greeting or your name?

The recruiting team sent me a few resumes of candidates who applied for my opening. I reached out to the ones I was interested to introduce myself and to invite them for a call with me. At least 2 of the candidates responded without the usual “hello” or “nice to meet you” nor even my name or thanks. Just “I am very interested in this role and am available at x time…. ” and then their name. Other candidates responded with “Hello —-“ and “Thanks”.

This role requires strong communications skills. But I don’t want to overreact or jump to conclusions.