I can't give you a definite answer on that. I know that card manufacturers have typically given them a RC for each series (K&N, ARCA, Trucks, Xfinity/BGN, Cup, etc) though those cards appear to both be BGN and Gordon's Cup RC's would have been 1993. I know some drivers have what is referred to as an XRC which is the first known card of the driver, but Gordon's XRC was a 1987 World of Outlaws dirt racing card. I agree that NASCAR cards could use some clarification on the RC. As an example, Haile Deegan's RC was in 2018 Panini Prizm, her 2019 cards are also rookies, and this year, the 2020 cards are also RC's. Only thing I can figure out for this would be where she raced in the different series. Maybe this helps a little. If you have more racing questions, you can feel free to ask me and I will give you the best answer I can.
Matt Kenseth card collection is nearing 50% with over 2300 different cards. Always looking for the missing remainders to get to 100% completion.