Can't really see how it would help. For shouldering the bike you want the front triangle to be as large as possible, preferably with a straight horizontal top tube so you don't end up twatting your shoulder with the frame every time you, well, shoulder it.
You always end clutching the frame angled forward anyways, a slight sloping tube won't make a difference. A curved TT should help to stop the bike sliding on the shoulder .
Help with cyclocross surely?
Plus those have limited tyres clearance don’t they.