According to an X account, Spotify added several new strings on its latest iOS update mentioning lossless support. It seems it's coming soon.

To be clear: Spotify’s lossless streaming still isn’t available yet. But these small lossless mentions and recent reporting indicate that the company may be ready to add lossless at long last.

It's been four years since Spotify started teasing its HiFi tier with lossless audio, but I guess we should stop hoping for it anymore.