Although your question seems a more retorically intended one than one out of true interest I wil nevertheless try to anwser it.
Epicrianthes stand quite far from the sections that you gave above. It needs a long list of pictures to show you that. Pictures of species that I sadly do not have.
Next to that the DNA tree of live is not finished so a true anwser based on scientific facts can not be given as yet.
But here I show you (and the other readers) a line of pictures of what very well could be a branch of this tree of life.
Cirrhopetalum to Sestochilus
First a real Cirrhopetalum. B. (or C. if you wish) longiflorum is one of the few Bulbophyllums that still belong to the section Cirrhopetalum
Next Bulbophyllum annandalei. Not a very big step. Especially things like colouration change very easily even within one species
You could very well stil call this a Cirrhopetalum.
Then the sepals are no longer atached. A very simple adjustment but if gives the flower a whole other look.
Next step Bulbophyllum bicolor.
Everything flattens out a bit.
And here we have Bulbophyllum lobbii a typical Sestochilus
I admit that this is a very blunt way of showing but I hope you get my point.
I can make you another branch by using completely different species. Thats why we need DNA to sort these things out for real.
From something as B. lobbii, evolution could go onwards into the direction of
or Bulbophyllum deviantiae
and maybe, eventually a simple Epicrianthes such as Bulb. cheiropetalum
Personally I have the feeling that the section lepanthanthes lies between the Epicrianthes and the other Bulbophyllum or at least hoovering close by.
I have no pictures of species from that section except of this undescribed species.
But species from this section such as Bulbophyllum inquirendum an B. lepanthiflorum are much more similar to the Epicrianthes having teh same pendent growth habit as most Epicrianthes and also carying the beautifull calli on the lip.
To make this long story a little bit longer. As you know there isn't a trua right or whrong in nomenclature. That's because we humans invented taxonomy and want to name everything. As long as humans have different ways of looking at things you cannot expect sciense to be as absolute as we hope it to be.
And have a happy new year (wich is right about starting in some places of the planet.