At the end of the article, GW called out that Warpbane Task Force, Hallowed Conclave, and Sanctic Spearhead still exist, and that they would combo well with the new detachments. This implies that they are at most 2DP, which is great news for us
I'm really hoping that Banishers is 2DP and Sanctic Spearhead is 1DP so that I can run combined arms armies in a really fun way, and also because it's gonna make Dreadknights really good if the rules for both either remain unchanged or get buffed
I think that GW has the opportunity to do something cool for the Agents, and that's to let us use a detachment for the units when they're allied into another Imperium army. For example, let's say I'm playing a Militarum Tempestus army and I wanna throw in some Grey Knights and Ordo Malleus units to make a Daemonhunters force. If GW is cool, they could let me take Bridgehead Strike alongside the Ordo Malleus detachment (and maybe a third detachment depending on if Bridgehead Strike is 1 or 2 DP), and I could run an army where my allied units still get some buffs from their detachment while the rest of my army gets Orders and Bridgehead Strike buffs