I think the writer seriously misinterprets the situation from the very get go of the article.
Nothing about the Duterte administration's moves to distance itself from the U.S. has every really been "populist", they have always been top-down initiatives by leadership with a prior history of left leanings mixed with realist geopolitical calculation. In a country where the the political establishment has always been tremendously right-leaning and highly inclined towards the U.S. (to a fault), the current administration has been unprecedented in its policies. As such any policy shifts it has tried to effect have been against the inertia of over a century of policy and political culture. Not to mention societal and cultural affinity built up during that time. One could argue that they would even be "counter-populist" given the potential pushback.
All that said...
The thing that really gets my goat though, is the bit where they allege the administration as having been "neglectful" to the promise of Bangsamoro autonomy. That is a grossly erroneous interpretation of reality.
Prior to the Marawi siege, the administration together with the Bangsamoro leadership had picked up the pieces of the last administration's failed effort and was working continuously though the Bangsamoro Transition Commission to draft a new organic law to be passed. Hell, I was in Davao to attend the meetings prior to and up to the official launching of the BTC. And then Cotabato for the first few meetings of the commission. All this in less than a year into the (then) new administration. Marawi blindsided everyone involved because from our perspective, the developments in the peace process were incredibly optimistic.
If anyone was to blame for any disillusionment with the peace process among the Bangsamoro it would have been the previous administration, who had somehow managed to snatch defeat from the jaws of victory. And even then, the people who took part in the siege were extremists (so-called "anarchists" in the words of Mohagher Iqbal) who were had pledged themselves to being the local front of the Daesh.
...But I suppose its gets to me more because I have personal stake on the matter.