No. The point to the Romans 14 passage is primarily about people who are "weak in faith" and the obligation of the Christian not to welcome such a person just to have an occasion for "disputes over opinions," as is plain from verse 1. One example about such contentiousness involves dietary concerns, as you have said. But he gives a second example about the dispute over the Lord's Day in verses 5 and 6. At the time, the dispute between the Hebrew Christians and Gentile Christians over which day was to be observed as the Lord's Day was still ongoing. Sure, the Sabbath is not explicitly mentioned, but it is clear enough that that is what is referred to in vv. 5 & 6. St. Paul didn't have to even mention the Sabbath by name, as ALL of his hearers knew quite well what he was talking about.
I'm afraid you are incorrect. If you read the Greek you will find no reference made to the Sabbath....or "the Lord's day". Not a hint....or implication.