YGO 2020 Tin - Rules of Play says:
The 2020 Tin of Lost Memories* shows the beginning of the ancient Duel between the Pharaoh and Priest Seto as depicted on the Tablet of Lost Memories – the very artifact that inspired Kaiba to create the Battle City Tournament! Each Tin this year will contain 3 bigger-than-ever Mega-Packs, each with 2 more foils than in last year's Tin Mega-Packs! So every 2020 Mega-Pack will contain 1 Prismatic Secret Rare, 2 Ultra Rares, 2 Super Rares, 1 Rare, and 12 Commons.