I wanted to thank you for uploading all the concept sketches from Kunihiko Tanaka's twitter, as well as giving them proper attribution and links. Lots of neat things coming from the 20th Anniversary concert, looks like!
I'm definitely okay with official concept art and sketches, when they're properly attributed and linked (if possible) to make it easier to find sources in the future. You've done that so far, so that helps a bunch!
As for suggestions on where to add the other sketches, the first one could possibly go on the page for Xenogears, Fei, and/or Elly.