I found this, quoted by Tim Love at Litrefs Articles, from Stephen Burt, so it's likely to be right,
"Young poets now tend not to believe that the
poetry they publish in books and journals can disclose organic preverbal
truths, invigorate broad movements for social justice ... When these
ethical spiritual, political, and historical ambitions fall away, what
is left is entertainment and craft or, to put it in another way,
technique and fun ... The sestina thus fits a poetics of diminished,
regretful, comic, self-skepticism."
I'm also very interested in The Incredible Sestinas Anthology, edited by Daniel Nester, 2013, which is likely to have got itself ordered before the evening is out.
The regularly trumpeted 'poetry booms' usually mean something fashionable like The Mersey Sound, performance poetry or a shouty, bad-tempered lady, not Amazon selling out of John Donne books. We are surely not living in a Golden Age, not even by C20th standards, which doesn't mean that the type of poetry described above, that I recognize as a point well made, is all there is, only that it is one thing that remains viable.
It can't be all there is because poetry can do whatever it likes. By all means do sincerity or something profound but if it's only similar to what went before ot's going to be little more than derivative.
All it has to be is any good.