The study mainly points out that the coal-exit goal of the "Power Past Coal Alliance" isn't sufficient in itself. It needs to be accompanied by other policies:

>These odds would improve if norms around sustainable growth or carbon pricing prevail instead71,72. Additionally, PPCA members can still galvanize Paris-aligned coal-exit momentum by immediately confronting freeriding sectors and ramping-up VRE, electrification and technological (and financial) transfers to freerider nations. > >Recent literature highlights the importance of complementing demand-side antifossil initiatives with supply-side actions73,74,75, for example, mining or export restrictions. This counteracts price depression and leakage, increasing phase-out policies’ self-propagation potential. Given geographical variance in coal quality and trade, however, policy efficacy depends upon the specific adopters. Crucially, the largest anticipated coal consumers in 2045—China, India and ASEAN members (Fig. 2c)—can each sustain self-sufficient coal supplies.

>Those coal-rich developing nations also exhibit the highest path-dependence of accession probability to near-term decisions. Most glaringly, China falls below the 50% threshold and Indonesia below 5% in brown scenarios. Additionally, we observe that several highly probable OECD coalition members install new coal plants in brown and neutral COVID recoveries. PPCA accession then forces a sudden exodus of unamortized capital from 2025 to 2030. Thus, to preserve the health of their economy45, citizens46, grid81 and credibility, OECD governments must cancel all coal projects.