When considering a candidate, how much weight do former titles hold?
If you're chasing titles, you might want to be concerned. I prefer to think about the long term plan and look for opportunities that further my career ambitions. Its ok to take a short term hit on title if you're going to be on a team where you earn lots of experience, credibility and get to work with some strong PMMs. In the long run this will set you up for the rest of your career.
From a hiring managers perspective, if there's a recruiter screening resumes, you might get filtered out by title. I prefer to go through the resumes personally to avoid missing strong candidates who might have misaligned titles. Usually a hiring manager will be aware of leveling across the industry.
Titles can be adjusted "to fit the role" but the real achievements are something harder to trick. That's why I always look for what the candidate achieved, why, and how. Those achievements can come under different from PMM title.
For example, marketing managers could be responding to GTMs, and content marketers for preparing customers' stories, case-study, and sales enablement. While growth managers/growth marketers could be doing funnel optimization for landing page, onboarding, and other stages of the customer journey. If I'm hiring for those tasks, I will be happy to consider candidates who successfully have done it before (even without a PMM title).
Former titles shouldn't be used as a main indicator of suitability. When interviewing candidates, I look for transferable skills and relevant experience. Some of the best hires I made had presales job titles or generic 'specialist' titles. Those hires made sense at that moment for these reasons - and hopefully, these contexts are helpful for you:
The gap I was looking to solve in my team was someone who was deeply embedded in the sales org, had great customer-facing experience and knew firsthand how to speak to customers, and understood our product & solution suite well.
We had an opportunity to directly impact revenue by owning product campaigns formally (this wasn't the case at the time), so we hired an exceptional community engagement marketer who was experienced at demand gen programs.