From Google: Unlike black spot and powdery mildew, crown gall (Agrobacterium tumefaciens) is a soilborne bacterial disease which infects root and/or stem tissue rather than leaves. Galls are most frequently seen as round, rough-surfaced growths near the plant's crown or on roots. These "crown" galls will eventually girdle the plant, resulting in poor growth and eventual plant death. Crown gall is a difficult disease to control once a plant is infected. It is best to remove diseased plants as soon as they are detected. Where possible, remove and discard all soil in which the root system is growing and replace with sterilized soil. If crown gall is a recurring problem in an area of your yard, it is best to rotate the area with a nonsusceptible grass crop for 3 or 4 years. Where a gall is restricted to stem tissue only, cut off the entire cane and immediately seal the cut surface with glue. Always sterilize cutting tools with rubbing alcohol after each cut of a cane with crown gall. During and after planting, take special care to avoid any and all wounds, especially near the soil line. Provide good winter protection to prevent bark cracking or other cold injury to bud union area. Never use crown gall-infested soil to mound over bud union for winter protection.

Update! I got all 8 roses in the ground today, and after 4 hours that is a magical journey I never plan to undertake again. I only had space to plant them about 3-4' apart, and I amended the soil with peat moss. Luckily this area has nice black dirt, no idea why, but it's one of the areas with better soil quality. I would have gotten a picture, but by the time I thought to, I was too filthy to go back inside the house to find the camera. Some highlights include spraying myself in the face with the hose TWICE, digging up a 6' honeysuckle tree to be planted elsewhere (it just showed up one day and I decided to keep it), clearing out the whole bed of overgrown daylilies and Bishop's Weed, and having to eventually take off my shoes due to caked on mud and just go at this project barefoot and crazy-looking as God intended. I also learned that accidentally touching rose fertilizer pellets with your bare hands hurts like hell. Good to know! Thank you everyone for your help! I will try and update if I have any further news as to how things are going.

I don't know where you are located or what you weather has been. I'm guess quite cool and damp. During weather like this strange things can happen. I was working by a daylily once. When I saw something odd as it turns out there where decaying tree roots in the area that sent up a giant morell mushroom. It had incased the roots crown and part of the scapes. Anyway at least your rose still has good canes growing so it's alive. May be best not to touch it till someone answers.

I interpret that you may be asking if there is a low level of bacteria from a gall infection still present in the rose when it appears to be cured. (Old rosarian has covered the insect type of gall formation.) I cannot give you a specific answer for the specific type of gall that infects roses (Rhizobium radiobacter), but in general plants can control low levels of bacterial infection with their immune system. " In most cases, plants infected with a bacterial pathogen cannot be cured. Even when symptoms are not present, bacteria still persist in the plant at low levels and symptoms are likely to reappear when conditions are favourable." https://www.ngia.com.au/Attachment?Action=Download&Attachment_id=1843 The following general article describes the biology involved in an infection: http://www.apsnet.org/edcenter/intropp/lessons/prokaryotes/pages/crowngall.aspx