We migrate to new infrastructure iteratively, migrating only those parts which are required at some moment. In bright far future all old tests will be removed, but it will happen not earlier than old frontend will be dropped from codebase. So you can don't rush with your own migration
Also note that js tests migration will occur only in 1.6.20 release branch (because 1.6.0 already branched and those commits are not backported here, and 1.6.10 will be bracnhed from 1.6.0, not from master)