Though it isn't clear if that is speculation or from a source. My guess is speculation but I think straying close to the time of the LOTR is more likely because anything else and most fans would be lost. A young Aragorn would be very doable and relatable with a great love story that we never see the beginning of. But the Silmarillion? The story is just too complicated and it doesn't have hobbits or wizards our really even dragons until near the end. Most people who are not serious fans would not even recognize it as the same story as LOTR. Most of the people I know who are not serious fans never finished the silmarillion.