I have done it but it seems like a very tight fight as is, adding a second onto every second dismiss pet (and theres something in the neighborhood of 50 required I think?) will just prolong the fight that much more, and the "enrage" of adds. Not trying to scream "sky is falling" but this annoys me lolHunter (Forums / Skills / Talent Calculator)
Dismiss Pet now has a 3 sec cast time (up from 2 sec). This is to discourage swapping pets in the middle of PvP to get a different form of CC.
I understand why they do it though. sigh