A lot of aspects of bridge design have been learned the hard way over the years. A skinny profile with a flexible deck turned into the Tacoma Narrows collapse. Scour, which seems so obvious, undermined the piers of the Schoharie Creek Bridge and taught us when to use piles instead of gravity footings.
While reinforced concrete did exist back then, it wasn't necessarily used or the need for it understood. In fact, concrete itself back then was different than it is now - different proportions of sand, gravel, and clay, different types of clay, different methods for curing, etc. Moreover, the lack of reinforcement is not the only problem here. Apparently the bearings (where the steel bridge superstructure sits on the concrete piers) have seized up. This means that as the bridge flexes due to heating and cooling of the steel, instead of moving as it should, it's been forcing the piers to move back and forth with it. So these piers have been impacted both by ice pressures below and the bridge itself above.
That's not to say reinforced concrete wouldn't have helped. It would be holding those cracks together and the risk of catastrophic failure a lot less. It could even have been possible to safely rehabilitate such piers. But given what I've read in the reports, this poor bridge is toast. Hopefully
these people don't file lawsuits and screw it up for the locals who need a working bridge in place. Note that there's no way the bridge could be open while being rehabilitated. In fact, the recommendation against rehabilitation is because it's too unstable to be safely worked on. And really, they need to get it torn down before the ice season starts because if it comes down on its own midwinter it will be a big mess, especially if there's an icebreaker ferry running at the time.
I would not expect to see a truss bridge replacement. Modern bridge construction can easily reach the spans (and heights) necessary using less aesthetic (but equally less complicated & less difficult to maintain) designs such as steel or concrete box girders.
