Does ios app Metadata rejected means binary is good

You do not need to upload new binary. They will review it again and approve it (or reject for other reason). It took only few hours in my case. But you can't be sure the binary has already been checked. Maybe they only did the metadata so far and will check the binary after your metadata correction. Anyway, no need to upload anything now.

Usually reviewers stop their review process as soon as they find an issue. This means that the metadata rejection can be the first of a longer list (hopefully no!) or that they reviewed your whole app and found the only issue at metadata level only: in such case fixing your metadata should be enough.

Recently I saw one of my apps rejected due to a mistake in adding an In App Purchase (basically the app was referring to an IAP still not in iTunes). After fixing it (no binary change, just adding the "in app") they found an issue in the app this time and then the binary was submitted. It would have been quite easier for me to know of the two issues together and fix them once, instead the triple-trip delayed my final app submission by 10 extra days (consider 5 days between two consecutive reviews)

From my experience, it doesn't always mean the binary is good. They may have very well reached the point of checking metadata and found an issue without testing the binary itself. Expect the Unexpected with Apple.