Honestly, I'd have thought that Dragapult being essentially freed thanks to Flutter Mane no longer competing with it for team slots would drop Palafin's viability or at the very least force it between some real teambuilding dilemmas.
We'll assume that Bulk Up Palafin-Hero manages to get in for essentially free and use a Bulk Up while you're switching in a very ordinary Specs Dragapult.
Bulk Up Palafin better be using Ice Punch or Zen Headbutt or be forced to Tera or it's getting 2HKOd, and honestly, a little chip means that non-Tera non-bulky Palafin-Hero is getting OHKOd by a bog-standard Draco Meteor (the Thunderbolt calcs are actually worse than the Draco Meteor calcs):
252 SpA Choice Specs Dragapult Draco Meteor vs. 0 HP / 4 SpD Palafin-Hero: 297-349 (87 - 102.3%) -- 18.8% chance to OHKO
252 SpA Choice Specs Dragapult Draco Meteor vs. 252 HP / 4 SpD Palafin-Hero: 297-349 (73.5 - 86.3%) -- guaranteed 2HKO after Leftovers recovery
252 SpA Choice Specs Dragapult Draco Meteor over 2 turns vs. 252 HP / 4 SpD Palafin-Hero: 445-524 (110.1 - 129.7%) -- guaranteed KO in 2 turns after Leftovers recovery
+1 252 Atk Palafin-Hero Ice Punch vs. 4 HP / 0 Def Dragapult: 362-428 (113.8 - 134.5%) -- guaranteed OHKO
+1 252 Atk Palafin-Hero Zen Headbutt vs. 4 HP / 0 Def Dragapult: 193-228 (60.6 - 71.6%) -- guaranteed 2HKO
+1 252+ Atk Palafin-Hero Zen Headbutt vs. 4 HP / 0 Def Dragapult: 213-251 (66.9 - 78.9%) -- guaranteed 2HKO
+1 252 Atk Palafin-Hero Jet Punch vs. 4 HP / 0 Def Dragapult: 109-129 (34.2 - 40.5%) -- guaranteed 3HKO after Stealth Rock
+1 252+ Atk Palafin-Hero Jet Punch vs. 4 HP / 0 Def Dragapult: 119-141 (37.4 - 44.3%) -- guaranteed 3HKO
+1 252+ Atk Palafin-Hero Jet Punch vs. 4 HP / 0 Def Dragapult: 119-141 (37.4 - 44.3%) -- 2% chance to 2HKO after Stealth Rock
+1 252 Atk Punching Glove Palafin-Hero Jet Punch vs. 4 HP / 0 Def Dragapult: 120-141 (37.7 - 44.3%) -- guaranteed 3HKO
+1 252 Atk Punching Glove Palafin-Hero Jet Punch vs. 4 HP / 0 Def Dragapult: 120-141 (37.7 - 44.3%) -- 2.3% chance to 2HKO after Stealth Rock
+1 252+ Atk Punching Glove Palafin-Hero Jet Punch vs. 4 HP / 0 Def Dragapult: 131-155 (41.1 - 48.7%) -- guaranteed 3HKO
+1 252+ Atk Punching Glove Palafin-Hero Jet Punch vs. 4 HP / 0 Def Dragapult: 131-155 (41.1 - 48.7%) -- 75.8% chance to 2HKO after Stealth Rock
+1 252 Atk Tera Water Palafin-Hero Jet Punch vs. 4 HP / 0 Def Dragapult: 146-172 (45.9 - 54%) -- 48.4% chance to 2HKO
+1 252 Atk Tera Water Palafin-Hero Jet Punch vs. 4 HP / 0 Def Dragapult: 146-172 (45.9 - 54%) -- guaranteed 2HKO after Stealth Rock
+1 252+ Atk Tera Water Palafin-Hero Jet Punch vs. 4 HP / 0 Def Dragapult: 159-188 (50 - 59.1%) -- guaranteed 2HKO
+1 252 Atk Punching Glove Tera Water Palafin-Hero Jet Punch vs. 4 HP / 0 Def Dragapult: 160-189 (50.3 - 59.4%) -- guaranteed 2HKO
By the way, the Punching Glove boost is assumed to be 1.1x according to
https://www.smogon.com/forums/threa...-data-mechanics.3709515/page-342#post-9398941. (The portion of that post that assumes that the Punching Glove stacks with Iron Fist is incorrect, though.)
Bulk Up Palafin-Hero loses quite a bit of its ability to stomp on multiple members of stall teams in the same game if it opts for Ice Punch instead of the Toxic-warding Taunt. ...And it loses its ability to anti-lead against Sticky Web and Trick Room leads, too.
Jolly Choice Band Palafin similarly OHKOs Dragapult back with Ice Punch (although Dragapult will likely be a coward and not switch into Palafin-Hero), but let's see how well Wave Crash does:
252 Atk Choice Band Palafin-Hero Wave Crash vs. 4 HP / 0 Def Dragapult: 217-256 (68.2 - 80.5%) -- guaranteed 2HKO (17.7 - 20.9% recoil damage)
...huh, Pult can't really switch into Palafin-Hero anyway.