I would like to think that's true. Some ENTs, like mine, actually think that tinnitus becomes chronic after 6 months.
Tinnitus Talk Support Forum
How does s/he define "fluctuating" ?
If the T is relentlessly on the same level, then I believe the chances of it going away are slim, whereas if it fluctuates, it could maybe disappear one day. However, as we can see on the forum, there are multiple cases where fluctuations are normal part of T after many years, hence fluctuating T can still be considered "chronic", in my opinion.
My tones change every second. At the moment its a bagpipe who plays the same 4 tones very fast. Maybe in half an hour there are four or five different hissing sounds...you never know