You don’t want a password reset confirmation mail from Andre, or in this case a simple account creation notification from Tom.
If it’s a full onboarding email where you are invited to have questions and interact further, sure, why not, assuming all following mails will be from Tom as well. Otherwise the mail having personality is just noise and abusing people’s social behavior.
I feel the same with mails addressing me on a first name basis. It’s skating on very thin ice, and I hate most companies doing it.
I think those personal emails are warranted if my first contact with a company was human, like I reached out and contacted someone from the sales team.
But "personal" responses to an obviously automated process like signup is just dishonest. If the founder responds to support requests - fine. Send me a personal response once I have a support request, but not as a signup confirmation.