I have a 100 as well, and I couldn't see myself replacing it with a late model 200, now that LC250s and GX550s are available.
It's quite a unique point in time as Toyota's BOF 4x4's all get redesigns within a very short period. This is Toyota's move to TNGA paying off, big time. IMO later model 200 values are going to drop like a stone over the next few years as 250s, GX550s (even 4R's? - lol) proliferate the market. Hard to think of a worse time to get into a later year 200 than right now.
Beyond that, IMO going from a 100 to a recent year 200 and particularly one gasser 4.7 V8 to another gasser 5.7 V8 - there's just really not enough reasons for me to do it considering the new alternatives now available. The biggest reasons I can think of are: "lower miles, newer rubber, some more power". Between the 2 legacy vehicles, the 100 drives better, the 4.7 is a more reliable drivetrain (not that the 5.7 isn't reliable), and the 100 is easier to work on over long term ownership.
However, to instead jump directly to a 250 or a 550 seems way more compelling: far superior performance (particulary the V6 TT), way better tech, better or equivalent ride & build quality, size / nimbleness is ideal, they will be mass produced (parts availability, long term support), warranty, etc.
A used 100 was our first LC. A new, maybe slightly used LC250 or a GX550 will be our next one. As great as the LC200 is, we'll be skipping over it.