Seems to me that if you can get your hands on the secondary application from their webpage, you might as well do it and throw it their way, regardless of what they do or don't say. From what I've heard of last year, in the notorious AMCAS crash of '01, Hopkins admissions heads had to sort through thousands of data-broken applications. The last thing they probably had on their minds was secondary application invites, and who knows, maybe some of that sentiment has carried over to this year (residual chaos, perhaps).
So chuck 'em in, says I. What can they do about it, return them with frowny faces stamped on? If they prefered to invite a select crowd of applicants to fill out the extra information, then it was their fault for making them freely accessible online. They've given you the go-ahead, so might as well go ahead!
best of luck,
~DB