NO! It will not save you from slouching. Slouching will make you need more rolfing.
Esther Gokhale wrote an excellent book on primal posture that covers principles I wish I had known decades earlier. Could have saved me a lot of future grief. In it she covers the history of slouching going all the way from old photos in the 1800s and early 1900s, showing people with perfect upright posture, up to when slouching first became fashionable in French magazines in the 1920s. Even shows how furniture gradually evolved to accommodate slouching. She covers traditional cultures and ancient statues and one begins to realize that slouching is a rather modern (neolithic?) phenomenon.
Over time as one ages, certain muscles begin to shorten and others begin to lengthen depending on what positions you hold for lengths of time and your muscles are what ultimately hold your skeleton in shape. Imbalances gradually become set in place with reduced range of motion. Just doing exercises may not necessarily correct shortened muscles and could even make it worse without doing the proper ones.
Pete Egoscue also wrote a book in which he states that people need to throw away braces and supports and train your muscles to hold yourself in place and there is a lot of truth to this although I make it a point use chairs that encourage sitting properly.
Rolfing and chiropractors may be useful at times and I have certainly seen my share of chiropractors over the years, but ultimately there is only one person in charge of your muscles and posture and and that's you. A rolfer or chiropractor can't strengthen muscles needed to hold your skeleton in position. Only you can do that and you can do it for free. In the primal, functional way of thinking, rolfers and chiropractors may be working to make you well, but they are focusing on a symptom after the fact and it's best to never need them at all and save the money. I worked my way back from a severe back problem in '08 and haven't seen a chiropractor in a couple of years now. N=1.
Gokhale's website - http://egwellness.com/ Just sitting upright my not be enough without understanding some of the principles she goes into. I've incorporated hip-hinging into my life and it's second nature now. Well worth the time to learn early.