Insurance companies are free to charge whatever the market will pay for their plans.
Wellcare has been around with similarly priced plans for at least 5 years. I've been on it for 4 years, my SIL for 5, and my spouse off and on for 4 years (her costly meds mean that a different plan is sometimes better). I check every year during open enrollment. I do a pretty complex analysis (including comparison to Costco and GoodRx prices), but Medicare.gov does a good quick analysis that will at least get you in the ballpark. It's always been right about the best plan for me. My spouse's is more complex - so it doesn't always choose the best plan for her when we buy meds off-plan.
BUT - even though we buy our Supplement from UHC, UHC has never been in the running for drugs, since it offered (for at least the last 5 years) either the highest or next highest set of plans in our area.
Just calendar a few minutes every October to check the prices so you don't make bad choices in the future. Wellcare seems relatively safe. It's had a good track record for the 5 years I've been checking. But you should never take it for granted that it will continue to the best (or even a good) plan.