Yeah, I think that is pretty well-established based on 'clues' such as the last year's ulster you mention and the weights listed on their MTM section.Yes, they told me the same that they don't list fabric weight anymore.
But they had an Ulster in that same fabric a year ago and it's weight is 670 gr/sqm
Still, it is less about the individual coat and more that I'm a little uncomfortable with the the practice of not giving out fabric weights, which Spier presumably ~does~ know, upon request.