Chakotay is my second favorite after Kes.
I realkly like Neelix and Harry is OKso I would really like to see them again.
Fair enough, everyone has their own favorite characters.
But the reason why we are seeing 7 of 9 again, is not only is she a popular character from Voyager, but her being a former Borg gives a personal stake in a Borg related story (even if its another party, like Romulan extremists using Borg tech for their own ends).
What is Neelix, Chakotay or Harry Kim's stake in this story? If they have no real stake behind being people associated with Star Fleet who want to do the right thing, they can be replaced with anyone in the franchise, they need a reason to be in the Picard show or any future show, which is what 7 of 9 has, a reason to be there. Otherwise, they could just be cameos. Heck Chakotay has a more personal grudge with the Cardassians over the Borg and the Cardassians are a nonentity by the Picard show era.
Another problem with all these characters is, they never really had a character arc in Voyager, so the vast majority of the regular Star Trek fans have no reason to care about them. Chakotay should have started out as a rebellious former rebel commander and slowly became Janeway trusty number one over time, instead it happens by episode 3, Harry Kim should do something to get promoted by season 3, giving him a character arc, where he became less green over time, instead he just stayed an Ensign the whole time and the writers gave him no real arc, why should I care if he is a captain now, when the Voyagers writers couldn't bother promoting past the rank of ensign. Neelix is still in the Delta Quadrant, so I am not sure how he could fit with this or any future show.
So the only way these characters will return is if there is a good story reason for them to return. Picard is the most incomic character from that era and 7 of 9 is a popular character who can fit in with this story, so its no wonder they are back.