[cbs]

Before you undertake the more significant time and cost of migrating platforms, you see what you can wring out of what you've got. It is possible that after improving their performance enough on Heroku (or hell, even without improving it), they can not justify the up-front money and resources to migrate platforms.

Or, for all we know, they could already be in the process of migrating away from Heroku, but that doesn't happen overnight and doesn't help their performance in the meantime.