No, that's not my objection. (Shameless self promo: read my fan fiction on this site and ask yourself if I have a problem with telling stories set in the "past").
Kell Hounds would be a direct prequel to events discussed in the Warrior series, and for that reason is less appealing to me.
It's like "Rogue One" I guess. The only way to make a story with a largely predetermined outcome interesting is to fill it with interesting people you genuinely care about, so it's more about the journey than the destination. With the Kell Hounds--i realize this may be a minority view--i feel they are too much of the author's favorites, so I'm not especially interested in them. Ymmd
I can see more potential for new and interesting stories with the Jihad, so that's more what I'd like to hear about, of the selections offered.