The law firm is Bird and Bird, and they are not that small.
So the whole thing really looks like legal bullying.
The S-type body shape has been in the public domain in the USA since 2009. One of the luthiers that Fender sent a C&D has hired the lawyer who secured that 2009 judgement against Fender, and he has been quite withering.
Fender have a huge uphill struggle here, and they clearly do not understand just how much time hobby guitarists with money spend watching Youtube. Big mistake.