Breast as pacifier?

Stacey • Baby Boy 12/5/2015; Baby Girl 6/6/2018, tiebreaker due October 2020
FTM, he's 1 month old today. So, I have been feeding on demand. As of 12/30, my guy would cluster feed occasionally, but slept 4-5 hours at night. Starting on NYE, he slept 30 minutes - 1 hour, unless he was being held, and wanted to eat CONSTANTLY... Like 20-30 minutes after finishing, he wanted to go again.
I figured it was a growth spurt, so I should just grit my teeth and deal, but we saw the pediatrician today (nurse practitioner) and she said he's using my breast as a pacifier. She stated that growth spurt feeding should only last a day or two, and he's developed a bad habit of snacking rather than long, filling feeds.
Any moms with insight here? He's growing, pooping, peeing, etc. I guess I didn't think he should go on a schedule yet, but seems like he should..