That’s not a promotion. That’s jumping ship and it’s smart. Your team member either sensed there was something wrong with your team or they were slapped with a layoff notice.
This doesn’t qualify you for a promotion. Promotions are based on the individual contributor who either consistently meets or surpasses some bullet point guideline that HR has. You can ask your manager about this bullet point guideline. You’ll see your level and the expectations the company has for you.
I’ll give you an example: junior level bulletin points may state that they’re expected to perform at a basic level and only contributing to their own tasks. The next level up will say that they’re expected to perform at a more independent level and making contributions to not only their tasks but also helping their team.
So ask yourself: what aren’t you i7 yet? What’s holding you back?
Truthfully you sound sort of jealous and believe in self-entitlement. It happens to everyone, don’t get me wrong. We often forget about these d-mb HR bullet point guidelines. There’s rules to follow, unfortunately. You have to play the game like the rest of us. It may involve Kool-Aid drinking.