If we were working on it, we wouldn't be talking about it. Whilst this topic was brought up in 2017, 5 Years of Skilling presentation, our plans and approaches have changed since then. In terms of skilling updates in general, give us feedback on what players would like to see.
https://www.reddit.com/r/runescape/comments/v7y6g9/tldw_539_june_developer_qa/
They never meant for a "construction rework". Making skilling content fun and for other purposes instead of reworking them is what they are doing.