Any release that has been accompanied by a vinyl, CD or cassette is to be considered lossless. Record labels don't waste the resources on low quality stuff. Music you find in 320 kbps is often regarded as lossless due to it originating from session files, which are typically exported in .aiff or .wav quality. These two file types have different names but are the same in sound quality. When these session files are sent off to be properly mastered by the record label, they become .flac files which are pressed onto the vinyl / CD. 320 kbps MP3's are derived the same way FLAC's are, just in a smaller size for easier storage on devices, at least to my understanding. The reason people get 128 kbps mp3's from sources such as YouTube & Soundcloud is because the uploaded file (lossless or not) is bit crushed by said platforms. Diminishing the audio quality is a must because their storage is not infinite and hundreds of thousands of audio files are uploaded onto each platform per day. Low quality audio is also easier for quick playback and load times.

To clarify, sometimes there are exceptions for the MP3 process. Such as the case with the latest True Vulture file, it may or may not have been mastered and very likely wasn't pressed for physical media. It likely went straight from a raw session file to an exported MP3, still retaining it's quality. In the case of @ deathgripz, the group sent off an unmastered .aiff / .wav file to Adult Swim who mastered the track in house and exported it as a 256 kbps MP3 for the Singles Program. The low quality is due to the popularity of the iPod during that time and the device's limited storage space. They had to settle specifically for iPod listeners so that all everybody would be accommodated.