Do doctors reccommend vaginoplasty to tighten the vagina?

No. Vaginiplasty is recommended for other reasons as cystocele, prolapse stress incontinence but not just for cosmetic reasons.
Yes. Vaginoplasty has its medical indications such as issues with pelvic organ prolapse.However, vaginoplasty can restore some of the tightness pts had prior to having children. Many women and there husbands may expirience lack pleasure and gratification during intercourse after childbirth due to lax vaginal muscles and connective tissue. Many physicians don't understand this affects quality of life.
Some do. Data do support that many women suffer with sexual issues when loss of support occurs in the vagina, usually after childbirth and as the years pass. Some women present with large bulges that are obvious and others simply have less tone and want more and many times, these women are excellent candidates for vaginoplasty. Find an experienced surgeon and do your research if you decide to go forward.