You read correctly! From Dr. Falkinham's paper:

(14) Pink Slime and NTM. Recently, by reading the article of Feazel et al. (2009) on
NTM in showerheads, we discovered that whenever a biofilm sample had salmon
pink-pigmented bacteria (Methylobacterium), there were no NTM. Based on that
information, we looked closely at the water in our Philadelphia M. avium patient
household data and confirmed that if Methylobacterium were present, Mycobacterium
were absent (Falkinham et al., 2016). Further work documented that a biofilm of
Methylobacterium spp. cells prevented the adherence of M. avium cells and a M. avium
biofilm prevented Methylobacterium spp. adherence (Munoz-Egea et al., 2017).
Evidently, the two cannot coexist in biofilms. Taps or showerheads in a home with
NTM don’t have Methylobacterium. As not all taps or showerheads in a home will have
NTM, use those that show evidence of a pink scum or film; the pink scum will be seen
on shower curtains, shower walls, or in crevasses in a shower or sink. As killed
Methylobacterium spp. cells can inhibit M. avium or M. abscessus adherence, I need to
initiate a project to identify the cellular Methylobacterium spp. component is sufficient
to inhibit M. avium adherence and produce that for premise plumbing and medical
equipment.

Here's the whole paper for your reference: