What do you mean a flawed argument? I'm not arguing anything. I'm explaining why they posted that message. If you want it to be easier to understand, imagine they said "It might not be 2015 anymore". "It's not 2015" is not a true statement, but in a matter of time it will be true. They literally never need to update that text. It's either still 2015 or it is not 2015 anymore. TrueCrypt is either still secure or it is not secure anymore. Either way, the statement "TrueCrypt may not be secure anymore" will always be valid.

If you think TrueCrypt will remain secure forever just because it's been verified as secure in the past, remember that there was a time when computers could not crack a MD5 code. When SHA-1 was considered secure.

I'm not arguing anything, just pointing out the obvious. Secure software today does not mean secure software tomorrow, especially if the software is not getting regular security updates. There is objectively no flaw in that statement.