Its not a Sabbath. The 7th day is the Sabbath. When the new heavens and new earth arrive we will be celebrating Sabbath eternally. As defined in the OT.
Isaiah :6622 For as the new heavens and the new earth, which I will make, shall remain before me, saith the LORD, so shall your seed and your name remain.
23 And it shall come to pass, that from one new moon to another, and from one sabbath to another, shall all flesh come to worship before me, saith the LORD.
And it shall come to pass, that from one new moon to another, and from one sabbath to another, shall all flesh come to worship before me, saith the LORD.
This says nothing about "celebrating Sabbath eternally." It does say that we will worship eternally, but that is it.
I don't have a problem with that.
SD