I just don't see that being true. Shatter and Disarm already exist in a form that insanely easy to use against shields (spell packets). And those two spells are pretty much the best option at 3rd level for celestial casters, so they are already pretty darn common. Despite this, shields are pretty much dominant throughout the Alliance. It is one of those skills that if you doubled the cost of it, most people would still buy it (I know because I conducted a poll). That is almost perfect elasticity (economic term).Also shatter and disarm work very different now and are much easier to use against shields. To the point that I think shields will be very weak in 2.0.
Even if fighters absolutely max out on Disarms and Shatters, they end up with fewer total per day (more Disarms, less Shatters) than a comparable celestial caster who maxes out on spells (assuming columns, not pyramid, which would be even more in the favor of celestial casters).
Yet, despite the prevalence of Disarms and Shatters already in the game, shields continue to be a hugely dominant mechanic. And I would argue that the primary reason is because Shatter and Disarm, as good as they are against shields, are a limited resource. A 20th level PC (approximately Alliance average level) only has, at most, 8 of each per day. Across the average day, that is maybe one per fight. Fighters will face the same limitation.
Of course, that only analyzes half the situation. The other half of the situation is how dominant Shatters and Disarms will be against PCs. And once again, I don't think there will be much change. NPCs already had access to Disarm and Shatter effects as spells, Magic abilities, Arcane abilities, by voice (*shudder*), and even as Elemental abilities if a plot team was feeling really weird. If the plot team wanted to overwhelm the PCs with these effects, it would already have happened. Allowing the melee version of the effect to be more efficient doesn't really change how much this effect challenges PCs, because that was always just at the discretion of monster desk.
I posit that the efficacy of shields used by NPCs is primarily limited by the access monster camp has to shields (for many monster camps, a much lower supply than warm bodies) and how well built those shields are (usually heavier and more awkward than PC shields). I posit that the efficacy of shields used by PCs is primarily limited by how aggressively the plot team targets them with Disarm effects (and to a lesser degree Shatter effects). I don't think these new rules change either of those factors in any meaningful way.
Note: Right now, basically any ritual on a shield also makes it unable to be shattered. I assume that continues to be true in 2.0, but I haven't been able to figure out if that is true or not. If not, and if Render is completely gone from the game, then THAT rule change would have a more significant effect on the game. But, as it is, Shatter basically stops being meaningful as soon as a player gets access to any type of magic shield.