MS.... congrats 
Hope it all goes well for you.. do keep us posted!
SM.... tongue tie does stretch with most babies, over here they won't snip it before 18 months as it usually resolves itself and can cause more problems snipped. I have it and it never affected my speech at all.
A however has a processing disorder as well, possibly oral dyspraxia, which affects his ability to move his mouth. Thus, as he wasn't moving his mouth properly the tongue tie never stretched. The ENT surgeon who recommended him for surgery said it wasn't possible for the tongue tie to cause a complete lack of speech but it does sometimes affect pronunciation and that's why it's usually operated on, a little boy from A's group SALT was waiting to have it done too and although his speech was very slurred he could talk.
A did have to have GA but we were in and out of hospital in 4 hours and he recovered very quickly, it's not going to miraculously fix his speech though, he needs to start trying to say words before we can work on pronunciation! He'll be under SALT for a long time to come hopefully but the aim is to have him speaking coherently by the time he starts school.
The paediatrician who dealt with him said a very large percentage of babies have it at birth, but a huge majority of these grow out of it. Your friends little boy may be like A with another issue on top of the tongue tie. A's tongue tie was more a symptom of his problem than the cause iyswim?
Breastfeeding is tough with tongue tie, my mother only managed a few weeks with me but I was losing weight and if A had been my first there's no way bf-ing would have succeeded as it was hellish.
I'd always recommend everyone do their own research rather than taking any HCPs word for anything as although some are excellent, many are talking out of their arses (like the paed who told me 'That child's not tongue tied' 
)