This info from the lexus forum seems to be pretty accurate
Sequoia was due for cancellation until 2015 (dealers begged), when a minor refresh was developed for 2018 and another for 2020, new model program was initiated in 2017.
2023 MY, as TMMTX is being renovated to accommodate Sequoia production starting in 2022. I believe that even tooling tests will be conducted for 2023 Sequoia next year, as it's already underway for 2022 Tundra and is where the photo in lighting came from. Tacoma is moving to Mexico-only production by end of 2021.
Also have 100% confirmation Tacoma is solidified for MY 2024, every body on frame USA Toyota for 2023MY has been fully styled and only one remaining is 2024 Tacoma (final design almost done), which is scheduled for Q3 2023.
So:
Spring 2021: 2022 Land Cruiser 300 (not for USA)
July 2021: Last of 200 Series arrives in USA
Late 2021: 2022 Tundra (Currently tooling assembly and final prototype testing)
Q3 2022: 2023 Sequoia (design is frozen, prototypes in testing)
October 2022: 2023 4Runner (design is frozen, prototypes being developed)
Q3 2023: 2024 Tacoma (wrapping up design process)
CY2023-24: Land Cruiser nameplate reintroduced to USA on smaller bodystyle (being studied)*
What's also interesting is the same source's past info has been spot on. And he said that the new Land Cruiser will probably come in to slot below the 4Runner - at least in size. An since there's nothing between 4Runner and Seqoia, does the 4Runner go upscale with $60k trim? Hard to know, but there's a big gap left in size there unless the next 4R gets even bigger? But this source says it will stay "true to form" and be a true update to the current 4Runner rather than a crossover or something else being badged as 4Runner.
The bronco apparently was what forced Toyota to re-think it's strategy on the land cruiser and maybe make something more like an FJ40, and less luxo-wagon. He said that the "heritage edition" was at least a suggestion of what the future vehicle might be more like. But if that's the case - it's nothing at all like a modern FJ40. So I'm not sure what to think based on this person's info. But, there's no doubt in my mind that he or she is either a direct insider or is being allowed to leak info in specific sets.
My opinion - Toyota is too late. 2024 model year is a long way off. I don't think I'll keep my 4Runner that long. It'll be 10 years, which is fine - but I'm ready for something new sooner. So maybe a bronco for a couple years in the middle? Or a new Tundra depending on price and details. That would put the 4R on a 14 year product cycle. Twice as long as the longest 4Runner model previously. The LC200 and tundra were also 14 years.
Also of note - he claims the tunrda styling was finalized in 2018, which seems inline with Toyota's long design cycle. And it will have 2 options. TTv6 and TTv6 hybrid. No N/A v6! so that would be great news. The hybrid would be with a turbo 6 not the regular 3.5 GR engine.