Where did you see that it was "indeed an 'Atmosphere'."? I didn't follow the stream, so was that were you heard it? I haven't seen a definitive answer on this one, but it sounds like you have.
It kills atleast part of the theory. So far, only the interpretation of what the different Purrs mean has been debunked. It may still contain a message, where sequences mean specific objects. Remember, the four symbols in the UP reply does NOT have the sequence believed to be a star (110 iirc). So, they basis for the theory is still there, but it needs more testing.
I'm still not convinced due to the randomness of when we start the sequencing. Someone did suggest to start right after it's done with its reply though, which is a good suggestion.
On another note. I know it's up for debate what symbols to use for what Purrs. Are Low represented as - or l? Who knows? That is why I always include both possibilities. If we use the wrong one, we may miss an obvious pattern. If we always use both (tedious, yes I know) then atleast we have a chance to spot it because we covered both bases. Another suggestion to use different symbology altogether is good, but I am afraid we can miss an obvious pattern that looks like the "four corner symbols" then a well, as our brain has to convert them and then see the pattern.
So, I know it frustrates you, but until we have a definite answer about which symbol refers to which Purr, I will keep using both. Sorry in advance