So what? Do you have valid arguments against what he says? If not, why shouldn’t he be allowed to complain?
He’s extrapolating from what he sees in TestLive and from Funcom’s track record from previous TestLive periods. In absence of new data, his concerns seem reasonable. It’s true that we can’t know until we see, but the point of raising concerns is to try to do something before it becomes a problem.
To make things worse, there has been absolutely no indication from Funcom that they’re willing to delay the release if one or more bugs prove to be critical.
Here, look at the official verbiage:
The focus is on preparing for post-launch updates and hotfixes, and no mention of pre-launch bugfixes.
Raising concerns is perfectly valid in this situation. Even if it doesn’t serve to make Funcom take action, it is useful to other players, so they’ll know to prepare for the impact.