Now it's time to download the IPA and iTunes 12.6.5.3 and start saving IPA files so you could use swiftkey longer than Microsoft would want you to do. I have one saved locally so I can still use it if I want to.
To anyone else, download the app IPA file now so you could use the app for a few more years. Also, local IPA is the only way to counter dev/Apple pulling apps. I fear Apple will also remove the app in your purchase history so you can no longer redownload it directly. (Vidget was pulled and I can only use it by installing it using iMazing)