Did AutoZone discontinue VR1 20w-50???...thoughts on Rotella 15w-40

Another oil thread. From 40 years experience: only 3 companies make the oil. Then it is re-branded. That walmart oil might be Kendall, only cheaper. Weight- 40 might help a loose engine for a year. Since the gov has been pulling zinc out of the oil; just buy some Lucas, or whatever.