Mozilla's lawyer just admitted to Wired magazine that, in fact, they do earn revenue from Pocket.
> Although the company emphasizes that Pocket and Telefonica didn’t pay for placement in the Firefox browser, Mozilla Corp. chief legal and business officer Denelle Dixon-Thayer told WIRED that Mozilla has revenue sharing arrangements with both companies.
Revenue sharing arrangement doesn't mean Mozilla included Pocket for money. Does Pocket even make money at a scale that could be remotely interesting to Mozilla? I very much doubt it.
I also doubt that Telefonica makes significant money with Hello. I can't even imagine a business model around this feature.
I suspect Mozilla was just opportunistic here and made those arrangements in case these features happen to generate revenue some day somehow.
(For me) it's mostly a transparency and trust issue. People widely suspected that it was Mozilla looking for another revenue source, they aggressively denied that money is involved. And now it turns out that there potentially is, but no details are published.
I actually think that with the way they did the integration, they probably should have received money (Otherwise, why not do a generic "read later" button and a way for services to register instead of adding a single, proprietary service). But for me, right now, the most important reason to use Firefox is trust in Mozilla, so I don't like it if it looks like they are not telling the entire story. (Compare to the advertising tiles: they clearly showed that they are receiving money for it, they also described what they did to preserve user privacy and security.)