No, doesn't have to be a C-section.
My waters went at 26 weeks, and we hobbled along, with regular testing and lots of bleeds, until 34w exactly. Baby showed as healthy in the many scans, but the bleeds were becoming uncontrollable + the risk of a full placental abruption became much higher.
I was induced on 34w exact, and DS came on 34w 1d. He was taken to NICU immediately, but never needed any help to breath. He had IV antibiotics (a precaution due to how long prior my waters has gone), light therapy for a couple of days due to jaundice, and was tube fed.
Babies only learn the suckle reflex at around 35w, in utero. So he had to be tube fed, and as I wanted to breastfeed, he'd be put to the breast, whilst he was tube fed, so he associated suckling with getting food. We were also recommend to use a dummy with him. I have a glorious video of him asleep, at 35w 1d, and the huuuge dummy bobbing up and down in his mouth.
I was medically discharged 36 hours after birth, and our NICU had a little apartment (Travelodge style) that I was able to stay in, as they weren't to busy with desperately I'll babies, and because I was trying to breastfeed. As it was lockdown, my DH was able to be at home with our almost 4 year old DD, so I could stay.
However, there was another mum in the same baby room (ward) who had a toddler at home, so she came in once or twice a day, and baby was tube/bottle fed. She would express at home, so baby had a mixture of formula and breast milk.
DS was discharged at 15 days old, exclusively breastfed.
Good luck with it all. I hope everything goes well, and you