Obviously harassment and toxic behavior are bad and should be discouraged but all this will accomplish is that politically-inclined editors will have even more weapons in their inventory to throw "harassment" and "toxic behavior" accusations at one another.
The bar to start contributing to Wikipedia is already very high: the way it works in practice, one must familiarize themselves with hundreds of pages from the WP: namespace, and learn how to use them strategically to defend their contributions. No wonder few people have the time and inclination to do that. To encourage more inclusivity this burden should first of all be lowered, not raised.
So, if more inclusivity was really the objective here, a better experiment would be to remove all the current policies except a dozen of the most important ones decided by popular vote among editors, and then edit them even further so that they fit on a single page, leaving these as the only rules in force. From then on, not more than a single policy change could be made per month, and all of it should still fit on the same single page. This would give new users an equal footing with the entrenched ones, with rules straightforward enough for everybody to understand and follow, which in turn should empower people to use their own judgement instead of being micromanaged. Disagreements would have to be solved by discussing the matter at hand, as opposed to flinging projectiles from the safety of the WP: namespace. Wikipedia could learn something from how remarkably simple the HN rules are in comparison: https://news.ycombinator.com/newsguidelines.html
OK, maybe the above is not the greatest idea but it'd at least rattle things a bit in the right direction if done as an experiment. On the other hand, much of what Wikimedia Foundation has been doing recently is tangential to the development of a free encyclopedia, and this press release is no different: it reads like an exercise in corporate bullshit that checks all the right boxes but will change exactly nothing. The response to the failures of bureaucracy is more bureaucracy: "What we were doing so far has failed, so we urgently need to do even more of the same. This time it'll work."