Regarding bridges, I think it's worth noting several major armies have fought across the area several times in the prior few years. It's quite possible the bridges not marked on the original game maps were destroyed at one of those earlier times, or as you've mentioned in the blog, simply too light to handle AFVs and heavier softskins.
The construction of the lake began in 1986, after T2K 1st ed was printed, so it's no surprise it wasn't included in the game. The dam includes a 4.89 MW power generation plant, so it's conceivable it was the target of a conventional airstrike or similar destructive action earlier in the war and not rebuilt. We know from the timeline that in September 1997 "NATO forces in Poland increase the rate of their withdrawal, practising a scorched earth policy as they fell back."
This is an easy, and logical way of explaining it's absence in the game, along with most of the unlisted bridges.
https://translate.google.com/transla...zbiornik_wodny)
https://youtu.be/04OEHRkXZf4