Using Google Play on a PC is completely legal and lawful at present. No laws are broken by doing so as it’s installed by default on the Android emulator called BlueStacks. Google has never prevented this emulator or any other similar software from having access to their app store and neither should we expect any major changes in this sense. However, as the owner of the platform, Google can always change its opinion whenever it wants and file lawsuits against third-parties due to possible dishonest uses of its infrastructure. Therefore, you can never trust 100% the legal situation of anything.
One last thing: beware of the final use you make of the downloaded apps. Just like everything in life, your legal liability depends on your own actions. It’s not the same to download the apps for your personal use than if you’re going to make money with them without belonging to you or carry out modifications that are later distributed online. In those cases, you can obviously get into trouble. Take into account that to install the emulator, you’ll need to provide a valid email address and that’s how Google can keep you located.