Cruz's parents and siblings (especially his mother) did pop up from time to time, but there was never a stable Castillo family presence at all times like there was for the Capwells. And, of course, having the Capwells be the only stable family on the canvas hurt the show in the long run.
I don't know if the public would be happy at either Eden or Cruz moving on but if one of them was going to do that would be Eden, as I just saw the Elena Storyline it's easy to see he wouldn't be moving on for a considerable time, Eden on the other hand was more practical in those matters, anyway the worst mistake was pairing Cruz with Kelly, that was certainly an atrocious move
I do recall a lot of relatives for both Cruz and Gina popping up throughout their time on the show but I don’t think I took to any of those characters. I saw the attempt to expand their circles outside of the Capwells but they weren’t very successful at it. In that respect, Julia fared better since she had ties to the Lockridges via Augusta so she almost always had 1 relative or pseudo relative on the canvas.
Eileen Davidson (Y&R, DAYS, SB) and Nancy Valen (RH) are sisters-in-law via the Van Patten brothers (Eileen is married to Vincent and Nancy is married to Nels). Here they are on the set of the 2020 Hallmark movie, Middleton Christmas: