There are new Medigap policies being offered by the private insurance companies. Some of these policies contained updated coverage to make sure that all of the gaps in Medicare are covered. They are also sometimes more expensive than the older policies. A Medigap policy that is older is likely to be less expensive to the individual because they may have gotten it when premiums were much lower. Needless to say, many people are interested in keeping their older Medigap policy rather than update to a new one.
There is no way that you can be made to switch to a newer Medigap policy if it is not something that you want to do. These are policies that are sold by private industry and you cannot be forced to buy a product from a private company. There are some companies that may discontinue the type of policy that you are holding. If they decide to do this, then they should offer you an alternative for the same price. There should be no reason why they should be able to force you to purchase a more expensive policy. Even if they have to upgrade you to a better policy, it is their obligation to keep you receiving the same rate.
There are some advantages to updating your policy. You will be able to have more of your needs covered for one thing. Usually the newer policies do not cost significantly more than the older ones. Typically you are able to get a newer policy for just a bit more. You never know when you might need to have that extra coverage to prevent high medical bills.