Ah well "You probably shouldn’t do that though" is just my opinion as the author. I didn't play a part in these changes. I just like Ruby enough to dig into their changelog :)
irb(main): a, b == 3
SyntaxError: syntax error, unexpected ==, expecting '='
I'll respond to your question by asking you a question. Which of the following expressions evaluate to "truthy"?
'truthy' if (a, b = []) # =>
'truthy' if (a, b = nil) # =>
'truthy' if (a, b = [nil]) # =>
'truthy' if (a, b = [nil, nil]) # =>
'truthy' if (a, b = [false]) # =>
'truthy' if (a, b = [false, false]) # =>
'truthy' if (a, b = [true, false]) # =>
'truthy' if (a, b = [false, true]) # =>
'truthy' if (a, b = *[]) # =>
'truthy' if (a, b = *nil) # =>
'truthy' if (a, b = *[nil]) # =>
'truthy' if (a, b = *[nil, nil]) # =>
'truthy' if (a, b = *[false]) # =>
'truthy' if (a, b = *[false, false]) # =>
'truthy' if (a, b = *[true, false]) # =>
'truthy' if (a, b = *[false, true]) # =>