That is not maxed out. It's a bullet truss nut. Fender had bullet nuts on their basses for quite some time.
Maxed out means there is no longer adjustment room to tighten the rod: you have reached the end of the threads on the rod.
'73-4 Ampeg V4B, Ampeg PF350,PF115HE, PF115LF, 115 Traynor, 1962 Fender Jazz, 75 Gibson G3, '10 Squier VM Jazz, Squier CV 60's P Sonic, Squier CV 50's P blonde, Epiphone Thunderbird IV