Funnily enough I think vintage space sets (and some misc other vintage themes) are some of the safest bets to not be remade (other than, say, one iconic set to cash in on nostalgia). What I think is more likely are sets designed to hit our nostalgia cores, like benny's spaceship (didn't fall for it, I got my originals!). Nexo Knights also notably had some nostalgic looking vehicles (wow this looks like sets from when I was a kid! *buys for kids but builds himself*) All this isn't aimed at you vincevaughn! It just got me on a rambling topic.
Many old lego sets go directly against their current mantra; nowadays sets part boost with many small pieces (the cheese slope and 1x1 tile era) and have minimal large parts since those are the most expensive (ugly rock pieces, large or raised baseplates, 8 stud + dimension bricks, huge transparent panels and what have you)
Old lego sets (compared to current) have very low parts counts for their price and would compare horribly ($80 for 350? $100 for 450? ehhhh...)
Some older molds are also retired/destroyed and are incredibly expensive to create, especially when the part is very large. Larger parts = larger mold = more tolerances to check, and more plastic to use. I remember reading designer blogs about new lego hires being surprised at the cost of some parts when they tried to include them in sets - you can get a bit more of an idea for this if you shop at bricks and pieces as well.
One mold I presume destroyed is the M-Tron Mega Core Magnetizer's wheels, which are already expensive anyway. It was produced in 3 sets, the Magnetizer, ISD, and a Mars Mission rover. These are the biggest plastic space rover wheels made by lego - haven't been in a set for some time. Fun fact: a knockoff's ISD uses a SMALLER wheel mold on their ISD! Probably means that mold is gone for good, like many other large, old parts. We could also talk about how technic's wheel and tire assemblies have changed in quality / size over time, but I'm a bit less versed in that.
Monorail molds are destroyed. People have been wanting them for years, but the parts are huge and intricate. Large intricate part means not cheap to remake mold, not to mention an isolated motor variant that doesn't fit into their (expensive to produce) power functions. *shoves monorail collection under desk* nevermind that. If monorail was reintroduced, I'd expect (and hope) it to be updated. The switches are honestly terrible anyway. (Side note: secondary market isn't even that expensive for monorails compared to MSRP. You can get either of the two space monorails for $275-$350 ea, complete, fully functioning, instructions included). That's really not bad, for how many people say they want the monorail, then buy a mass produced SW set for a comparable price.
This honestly goes for most classic sets - many are not astronomically high to collect or buy, especially when you compare to the prices of non-iconic, new release lego sets. To re-engineer monorail tracks, molds, motor, and produce, there is probably such little margin at ~$300 pricepoint they'd rather just be pumping out jokerlands instead.
The newest track system is a roller coaster as seen on the joker manor thing, which honestly is long overdue anyway (especially after the hilarious letdown of the friends coaster). Notice how it's mostly thin plastic? Cheaper than a thick, solid beam like a monorail track. I'd expect more part variants for tracks on this later - this first set introduces them and includes minimal track length (cash in on that new part appeal), once normalized, they will develop and release more based around it (gimmie lift hills, banked turns, and loops! Flexy track!) Knex roller coasters were their cash cow for a long time, might still be for all I know, and it's about time lego found a working model for it, even if we need some more track parts to really make anything cool.
I'd love to see a cataloged list of new parts within the past decade (is there a good comprehensive list somewhere?). I'm betting most of them are very small (cheese slopes, pie tiles, tile variants, little plates / clips). Again, very cheap to produce in mass. Bloats part counts. Technic may be a bit of an outlier with large specialized molds (which are still not cheap however).
Just to add: remakes are not new! They are tried and true, but will probably become more common. I am not saying every set ever, it's really a convenience and case by case basis thing. More sets in the history catalog, more to choose from. Iconic sets with basic brick inventories (no new molds) are most likely candidates.
They rereleased the iconic lego Metroliner Train (and dining cars), and Main Street 6390 from 1980. I sure was happy to get some dining cars.