This is a user to user forum, and none of us has any insight into any future changes or additions to PD. FWIW I've been editing for 10 years and haven't ever heard of Bink video or BIK files. Since it's a proprietary format, it's possible that Cyberlink won't even be able to license the decoder, and I have no idea if they'll want to spend the time and effort to reverse engineer it like the folks at ffmpeg did.

Meanwhile, you already know that Handbrake will convert them, so you do have a way of editing clips in PD, even if it takes an extra step.

If you want to request that PD support that format, the best way to do so is to use Rate Us & Provide Suggestions under PD's File menu.