The BING cache of the Yamaha USA Montage site (before it was taken down) did not specify these features...
Is the Montage the Motif/MOXF workstation replacement or a new "Performance Synth" (e.g. SY99, Jupitor 80) product line?
In our discussions with Yamaha last Summer they were only talking about a replacement for the MOXF but they did say it would be a completely new line of keyboards that would not be 'Motif'. When we asked about a replacement for the XF they would not comment but I can't see how you could replace one without replacing the other.
From what I have seen so far Montage doesn't appear to have user sampling or a midi sequencer however it does have flash ram so I assume you could load new samples and waveforms as with the XF/MOXF
As for sequencing I'm not sure. Personally I never use a built in sequencer, preferring to hook up to a DAW as it's more convenient and more powerful, for me anyway.
Maybe Yamaha are moving the whole keyboard workstation thing in a slightly different direction to reflect the times we live in?
'Motif' was a great line of keyboards but in 2016 I think we need something completely new and Montage seems to be exactly that.
We will know all in just a few days time!
Saul
Yamaha Forums UK