While I agree it is normally BS, back a year or more, there was a bug in the DJI Inspire 1 TB48 then current firmware such that if you left the battery at storage charge over the winter months then it would enter the "automatic" discharge mode -- but it didn't know when to stop, so it would take the voltage down to zero (or close to), thus trashing the batteries. I have four TB48's that were toasted because of this bug. So it could be that that was the start of this "alternative fact."
DJI's alleged Customer Support refused to take ownership of the problem asserting 1) the batteries were puffed up and 2) they were now out of warranty. They were not persuaded by the fact that the batteries were not out of warranty when I put them into storage, and the reason they were puffed up was because the DJI "smart" firmware was dumb enough to over-discharge the batteries thus causing them to puff up. Sigh.
That said, in my experience with other aircraft, "normal" LiPo's, taken to storage voltage, will happily stay there for quite some time -- I have some that have been at storage voltage for more than a year or two -- I don't know the exact limits because none of mine (other than the TB48's) have ever been toasted by holding them at storage voltage for long periods (e.g. a year or more).
However, before I bring a LiPo that's been in storage for a long time back into service, I will charge it, then discharge it down to storage voltage a couple of times (I use the Hyperion SuperDuo that has this capability). I do this more to make sure that the LiPo will function (albeit under light load during the discharge cycle). I do have a honking great dummy load discharger that I can use if I really want to simulate flight loads and discharge at 50 - 80 Amps. My initial report on this topic (now three years old) is
here. I still have all the original Lipos that I used for the tests and I've held them at storage charge for three years, so I plan to re-test them to see if their performance (capacity and discharge curves) have degraded by being at storage voltage for that long.
Hope this helps...
Andy