Well, I didn't say all of their talent left. Wataru Ishibashi was an incredible musician who stuck on board with Falcom, but sadly he died at 39 in 2014 (he was the composer for Silver Will, one of the most iconic songs in Falcom history, from Trails in the Sky.) Takahiro Unisuga is another big talent who's been working on games with them since Xanadu Next and is still making music for their games. Hayato Sonoda worked on Vantage Master back in 1997, and he's still at Falcom making awesome tracks as well. One of their more prolific (and contracted) composers, Mitsuo Singa, is less awesome but he's been improving a lot lately.
It's harder to tell you about the awesome internal artists that are currently working at the company because most of them, whether it be art or music, aren't credited directly for their work. For example, we have no idea who the current lead artist doing the character art for Trails is right now, but we can start to guess. It's easier to talk about the talents and their contributions in the OP because they're no longer at Falcom.
Random example: the artist behind the awesome Baccano! light novel and anime series (and for Star Ocean 4's illustrations), Katsumi Enami, did work on Ys Seven for Falcom, alongside Trails of Zero and Trails of Azure. HACCAN did the promo art for Trails sometimes - the artist that did the Mushihime-sama cover. The thing is, because Enami was credited for certain Falcom titles, there is often confusion about the fact that some of the internal artists follow Enami's style closely or emulate it so people credit that work to Enami mistakenly.
You can see Enami's prowess at character design in one of Adol's best designs in franchise history:
This was more a tribute to Falcom's influence in the industry.