That would not contradict the Guardian reporting, or even what the NSA's slides claim.
The rest of what you state also does not contradict Guardians reporting: They make specific claims about specific subsets of these companies data.
You keep arguing about an expansive interpretation of the reporting even when faced with much more restricted alternative interpretations.
When comes to relying on press releases with denials, I'm clearly more cynical than you - I assign them pretty much zero value as evidence. I'd expect these companies to issue denials whether the claims are true or not, so I don't see the press releases as containing any useful information to draw inferences from.
Anyway, I've disagreed politely with <tptacek> before, but he is 100% correct here.
Other reports have corroborated this.
Declan McCullagh, who has covered this beat for CNet for something like 10 years and is most notable on HN for jumping into threads and arguing the EFF's side of any given story against me (in other words: not a guy prone to support of the establishment), ran a story last week with sources that also denied that NSA had unilateral access to Google Mail.
The NYT just a few days ago ran a story with a linked FISA court order that documented Yahoo's attempt to push back on a FISA directive, a process that would not have been necessary (for the government) had NSA had direct access to Yahoo's servers; the court order demanded that Yahoo turn over data.
And, of course, Google categorically denies that NSA has direct unilateral access to their servers and, for that matter, that they've been able to obtain records for large fractions of their user base. Those denials have come from multiple levels of the company, from the CEO to the General Counsel to their tech leaders to people on their security team.
I'm not simply supposing that NSA doesn't have this access. Based on the evidence available, I am drawing the obvious conclusion that they do not.