Oh cool, never knew that. Even so, good defensive typing and decent bulk is nice on Genesect and Garchomp anyways. I run HP Ice because I get scared of the scarf Salamence Fire Blast and the Dnite Fire punch when putting them up against Genesect.
Chandelure Psychic damage calcs:
Bulk Up set
252 SpA Chandelure Psychic vs. 120 HP / 136 SpD Conkeldurr: 252-298 (66.14 - 78.21%) -- guaranteed 2HKO
(252, 256, 258, 262, 264, 268, 270, 274, 276, 280, 282, 286, 288, 292, 294, 298)
Fire Blast: 66.14 - 77.95%
Status Orb set
252 SpA Chandelure Fire Blast vs. 128 HP / 128 SpD Conkeldurr: 255-300 (66.57 - 78.32%) -- guaranteed 2HKO
(255, 258, 261, 264, 267, 270, 273, 276, 279, 282, 285, 288, 291, 294, 297, 300)
Psychic: 66.31 - 78.32%
252 HP/0 SDef
252 SpA Chandelure Psychic vs. 252 HP / 0 SpD Conkeldurr: 304-358 (73.42 - 86.47%) -- guaranteed 2HKO
(304, 306, 310, 314, 318, 322, 324, 328, 332, 336, 340, 342, 346, 350, 354, 358)
Fire Blast: 73.18 - 86.23%
252 HP/252 SDef
252 SpA Chandelure Psychic vs. 252 HP / 252 SpD Conkeldurr: 220-260 (53.14 - 62.8%) -- guaranteed 2HKO
Fire Blast: 53.14 - 62.56%
0HP/0 Sdef
252 SpA Chandelure Psychic vs. 0 HP / 0 SpD Conkeldurr: 304-358 (86.6 - 101.99%) -- 12.5% chance to OHKO
(304, 306, 310, 314, 318, 322, 324, 328, 332, 336, 340, 342, 346, 350, 354, 358)
Fire Blast: 86.32 - 101.7%
Similar damage. I'd rather have HP Ice that does 4x Super-Effective to more pokemon than a 2x Super-Effective move that counters only one pokemon and does around the same damage as Fire Blast already does.