No it’s not, its the literally the name the government gave those plans.
“What is Medicare Part C?
A Medicare Advantage Plan (like an HMO or PPO) is another Medicare health plan choice you may have as part of Medicare. Medicare Advantage Plans, sometimes called “Part C” or “MA Plans,” are offered by private companies approved by Medicare.”
“What is Medicare Part C?
A Medicare Advantage Plan (like an HMO or PPO) is another Medicare health plan choice you may have as part of Medicare. Medicare Advantage Plans, sometimes called “Part C” or “MA Plans,” are offered by private companies approved by Medicare.”
https://www.hhs.gov/answers/medicare-and-medicaid/what-is-me...