These articles all are very vague and do not provide nearly enough information to allow anyone to form a reasonable opinion. First, EAL2 is no where near the highest level of evaluation. More importantly, even if it was evaluated to EAL7, we have no idea what that means without looking at the protection profile (PP). The PP defines the features that are looked at for the evaluation. Without knowing the PP, they could be evaluationing Linux or any OS only for it's ability to control access with a username and password. So in theory, that could mean that once a username and password are provided, the user has unlimited access to all files on the system. As long as that feature is documented, mathematically modeled, and tested correctly it could get a high EAL rating.
The biggest thing to remember about the CC is that the level rating is relatively meaningless without considering the protection profile. The problem is vendors don't readily tell you the protection profile they use.