Kids/babies go through ALL kinds of "phases." They and their behaviors are NOT static.
Your daughter IS self-soothing... using a pacifier/thumb sucking are all considered manners in which a baby self-soothes. If you research the topic, you will see this.
Just as an example: My firstborn, my daughter.. was very difficult to put to sleep or nap. She never really got attached to anything nor did she self-soothe very well, unless she was breastfeeding. Needless to say, it was very tiring. My son on the other hand, very adeptly had "found" self-soothing ways in which to fall asleep... he likes to sleep on his side or tummy, he likes to sleep with his stuffed cow, and he likes his pacifier.
1) You can do what you are doing now- take away the pacifier cold turkey...and have her scream it out until she is so tired from screaming that she passes out and falls asleep this way. This will go on for a few days...not only at night.
2) you can let her have it... and realize that they DO grow out of it. Some well known doctors let THEIR own children have pacifiers until they self-wean from it.
3) you can decide for her and perhaps feel "self conscious" that your baby is using a pacifier. (for some reason...outsiders seem to look down at babies & Mothers who "let" their child use pacifiers).
4) Do research on pacifier use & thumb sucking... MANY respected Doctors/child specialists do NOT abhor pacifiers...in fact, it is a healthy part of "self-soothing" etc. Even in the womb a "baby" will suck on their thumb etc.
5) Decide "why" you want her to quit the pacifier...based on her habits when she was only 4 months old.
6) See if it IS the pacifier that is causing "problems" for your baby.... OR if it is perhaps just a part of "developmental" changes and phases which they naturally go through biologically and physically and cognitively etc.
7) Maybe, it just so happens that in tandem with the timing of her pacifier use... she COULD also be teething.
8) All babies go through changes. My son is the easiest baby... he could self soothe from early on, takes 2 naps a day, sleeps well at night, is independent & good natured... but from about 6 months of age he got attached to a pacifier even though we did not push it on him. It was just laying around and he grabbed it and stuck it in his mouth. It doesn't bother me at all nor my Hubby. Yes, it helps him to sleep. No big deal, to us. We know, that he will wean himself from it as he gets older. It is not forever. Myself... I had a ratty-ol blanket and sucked my thumb until I was in Preschool age... my parents never pressured me about it. BUT through my own maturity I knew not to do it in public, and I didn't. My Parents never ridiculed me or made me feel "wrong" for it. Then one day I just stopped.
9) If you do want her to stop using a pacifier... try cutting the tip very slightly or make a little hole in the tip...it will change the "suction" of the pacifier making it less attractive or useful to the child and not as "fun."
10) YES A CHILD CAN "RE-LEARN' HOW TO SELF-SOOTHE. No worries, really. She's 8 months old now... and nothing they do is engraved in stone at this age...from week to week or month to month they are constantly changing and developing. More "phases" WILL come up.
11) It's really up to you as to when & how you want to handle the pacifier "problem." There are MANY different approaches and attitudes toward pacifier use. For me obviously... I have no problem with it, and I refuse to let other people "stare" at me and my son and make us feel uncomfortable about it. He is just a child... and they grow up so quickly... and I certainly will not make him feel "weird" about it. It will not be forever. I know that one day the pacifier will be gone. In some cultures it's not so looked down upon. In our culture, it is.
Well, sorry for rambling. Really, do what you think is best for your baby... and for you. Do you want to wake up 5 times a night? At 8 months old, sure the pacifier will drop out of their mouth as they sleep, but she can get it back in her mouth if need be and find it. Self-soothing can be a fickle thing too... don't worry that your girl "lost" the ability to do that. Babies are very resilient.
Take care, all the best,