From the comments, you can see that at very least you're not making any major errors with the phrase. But I think you are right to be suspicious of it, primarily because it is using an idiom to mean something different from the normal use.
The actual idiom is "the early bird catches the worm", but a key aspect is that the later bird does not catch the worm.
Your meaning seems to be more closely captured by "early adopter"; i.e. those who are early do get an advantage, but it's nothing more than that very earliness of access. Those who come later still get stuff too. Although even here, it's not a perfect fit since it connotes early adoption of a product or service, not simply being among the first to read material on a new website.
Overall, you won't be sued or put in jail for using your phrase, and as you can see from the comments, at least two native speakers are OK with it. But I'd be willing to bet that even though they're not faulting it, they as native speakers would not have chosen to use that phrase themselves. :-) If it were me, I wouldn't use it. Or, if it grew on me so that I decided to go for it, I'd perhaps add some support for it – e.g. a graphic of a happy little bird pulling an article (instead of a worm) out of the ground.