Solder is superior as it allows for better heat transfer. On the Intel platform, delidding is a common practice among overclockers because the chip giant uses poor-quality thermal interface material (TIM). By swapping it, users can achieve better thermal performance, and thus higher overclocking results.
The Raven Ridge APUs are budget chips with relatively low TDPs so the impact here will be relatively low. However, it's unknown whether AMD will continue to use solder for its upcoming Zen+ (Ryzen 2000) series desktop processors. As Hardware.Info points out, it wouldn't make sense for AMD to use multiple packaging lines. So perhaps this is indeed the end of solder.