The real problem Mozilla has is eroding trust. They're not the first (Windows 10 practically auto-installing itself is another example, or heck, AMBER Alerts on my phone) but it's the same idea: power has to be used wisely.
When I see something as arbitrary as Pocket just show up as one of a handful of toolbar items, my reaction is no longer "oh good, a Firefox update"; it switches to "great, what crap have they auto-installed and enabled-by-default this time!?", to finally "turn off auto-updates".
Same with AMBER Alerts. In theory, a good idea. In practice, every single one of them has occurred at an odd time of day, presenting itself as important but turning out to be the vaguest, most unhelpful text message I could have come up with. Solution? I had to turn them off. A good idea, ruined, by a stupid application of that power.
After looking at the available sources, it seems all quoted claims very specifically only said "Pocket didn't pay for the integration", so technically a revenue sharing agreement established later wouldn't be covered by this.. Technically...
* https://news.ycombinator.com/item?id=9668285
* https://news.ycombinator.com/item?id=9885360
* http://www.pcworld.com/article/2930532/reading-service-pocke...
I think (and hope) they just misinterpreted "didn't pay for inclusion" as "doesn't involve money", not that they deliberately lied to us.