Even though Picard won’t be in Starfleet anymore by the time his show begins, he and his old crew went through a lot together, and someone as stalwart as him would hardly just lose touch with people he survived life and death situations with on multiple occasions.
OK, so this is in no way a confirmation that LeVar Burton will get the chance to reprise his role as chief engineer Geordi La Forge, but he did appear to be pretty confident that it makes sense for Picard to keep in touch with the old gang.