Hey about on-board samples.
What you say is indeed true, but only partially. You're right, some of the old samples are being used on newer synths like the Yamaha MOtif, Korg Triton and ROland Phantom series.
But by the same token tons of new ones are being added.
For example my MOtif ES8 does feature some samples from the W5 and Sy series but they only make up a small fraction of an entire ROM sample data of an instrument. MOre like only 8 megs out of over a hundred.
So, nope. You are missing a lot more than just arpeggiators extra FX/DSP and sampling.

-ED-