xD I see 4 possibilities:

1. My powers of deduction are extraordinary, perhaps even rivaling Sherlock Holmes.

2. My intelligence and deductive powers aren't exceptional, but rather there are alot of people on the internet who possess below average intelligence.

3. It was all just wishful thinking on the part of PC gamers.

4. People were looking for anything they could find to downplay Xbox One after it's success this Holiday season, so their delusional minds stuck upon the wording of that beta description, and they decided to run with it to downplay Halo 5's system selling capabilties next year.

Not neccessarily true. Halo 5 as an exclusive sells alot of consoles, Halo 5 as a timed exclusive sells less consoles. The bigger the sales gap between PS4 and Xbox One, the lower the number of games that Xbox One recieves becomes. If PS4 takes a big enough lead it'll start getting 3rd party exclusives by default, in other words Sony won't have to buy some exclusives, some developers will start choosing to release solely on PS4 because it's easier than developing for multiple platforms and because PS4's install base is big enough for their games to turn a profit. We saw this in gen 6, PS2 sold extraordinarily well compared to Xbox and Gamecube and as a result it got lots of 3rd party exclusives by default, in fact PS2's game library was more than 3 times bigger than the game libraries for Xbox and Gamecube as a result of it's huge sales lead. In fact we're already starting to see this effect again this gen due to the PS4's early lead, PS4 is starting to get exclusives by default, mainly in Japan where the gap between PS4 and Xbox One is biggest, but PS4 is even getting a few western exclusives by default.

The smaller the gap between PS4 and Xbox One is, the more difficult it becomes for 3rd party developers to ignore an Xbox One release. Therefore any game that sells Xbox One's is important to Xbox One owners, and Halo 5 is perhaps the single most important game to have as an exclusive. 

Are you seriously going to compare Halo 5 with Dead Rising 3?

I am not comparing games, I am comparing PR statements.

Then compare the PR statements with other Halo games.

Oh, but X360 Halo games never came to PC, so they could not call them timed exclusives coming to other platforms.