With errata finally being dealt with I think I can understand why the TM book might be delayed. some problems\ might be dealt with then removing the need to fix them in the TM book.
No, the problems with TMs need more. Unless you count 'ground up rewrite' as 'errata'.
Honestly? The TM rules read like whoever wrote them hated that they were even in the game, but didn't have authority to retcon them so they went out to make them noticeably and demonstratively weaker than all other matrix users. They went from being the 'Swiss Army Knives of the Matrix' to having to hyperspecialize along a single character path to have a hope of being even half as effective as a decker, and a whole stream was basically told to f*ck off until they Submerged. In 4E, TMs had the tactical advantage, but tended to be glass cannons, especially when they took Matrix damage directly to their brain. Deckers, on the other hand, had the strategic advantage, being more reliable and harder to kill, while still being quite effective at their job. On the rigging side of things, TMs could be great single vehicle/drone riggers, but actual Riggers were better at multiple drones, swarms, and were, again, harder to kill since they didn't take damage to their brain in the Matrix. There were legit pros and cons to each side, which made things more of an option.
Fast forward to 5E, and we start with Priorities. TMs need good numbers in Resonance, their mental ability scores, and skills. Which means anything other than a Human (or maybe Elf) TM is going to be severely gimped in other areas, and probably starting with jack-all in resources, to boot. Of course, this isn't a purely TM problem, as it is one of the hallmarks of the Priority system in actively discouraging people to try things like, say, a Troll Mage or a Dwarf Technomancer, and so on. Things that were easily possible in 4E are extremely difficult in 5E due to actively seeking to limit and even stripping out customization altogether in many places (Weapon mods, anyone?). But while a Mage really only needs two attributes (Magic and their casting stat, with a decent third in Willpower), a TM needs all mental attributes at high levels to even think of doing more than a hyperspecialist role in the Matrix. And they need all the same skills as a normal hacker, plus new ones. And then you have complex forms, and so on. And heaven forbid that they actually want to buy anything like a fake SIN, or a lifestyle above Squatter!
In 4E, TMs were the swiss army knives of the Matrix. In 5E, unless you're playing it as a pet class focusing on sprites, you don't even break even against a decker, and you have no adaptability, at all.
As I've said before, TMs this edition got thrown in the cell with Bubba the Love Troll, and sandpaper for lube.