I'm pretty torn on this one. It'd be super cool to have Iggy back in a Flames uniform for some actual hockey games (rather than some sort of ceremonial retirement or whatever), but it's also far too early in the season still to even be entertaining the decision. The team's current run will end and it's possible that they may slump again at some point, so an assessment has to be made closer to the deadline as to whether or not this is the sort of piece the team should really be chasing.
Secondly, I can't think of many players on the team right now who I'd prefer to sub out in favour of Iggy. Chiasson's way younger and is probably more versatile than a guy like Iggy, who you'd be bringing in to play a fairly niche role at this stage I'd imagine.
All of this withstanding...tough call.
Edit: I should also add that I also don't foresee there being much chance of this actually happening. Treliving has no sentimental attachment to Jarome and seems far too shrewd to pursue some nostalgic quest to get Iggy back in a Flames uniform.