Different litecoin address types and support of "legacy" addresses


I just realised that there are at least three types of LTC addresses out there: Starting with M*, with 3* and with L*

My coinbase wallet was not able to process the M* version, but the 3* was fine.
I just created some paper wallets starting with L* and stored some coins on the wallets. Now I am wondering, whether this will be a problem in the future? Are there any plans or rumours to discontinue support for L*-wallets?

Do you have any general advice on how to proceed?
Thanks and cheers