The article you listed reads more like preliminary research more than anything else, and aside from medical school, I have done research into drug expiration on my own given that I have multiple complex health problems and I need to know how long I can count on my medication being effective if I needed to stockpile it. My background education in organic and general chemistry tell me that the two biggest concerns are humidity and temperature. You can also get information from the drug manufacturers about storage recommendations and cautions about efficacy following improper storage. If humidity or extreme temperatures (like where I live in Minnesota) come into play, the guidelines get a lot more fuzzy.

Also noted in there, a concern with antibiotics in particular is, that while they will retain some efficacy, the diminished effects over time can lead to more problems with resistance, and that can become important in a single individual depending on their colonization status and how often they end up needing to use the antibiotics.

Don't get me wrong, keeping a stockpile of medications is important (I'm trying to build up a buffer that I cycle out for some of my more critical medications) but it has to be done with cognizance and awareness of the pitfalls of such a practice. Personally, I would not trust my life to medication that has been expired for more than about 3 years if it is at all avoidable which is why I cycle my stockpile each time I get a refill. (i.e. putting the new meds in the storage container and taking the ones that were in there so that the storage is never more than a couple months old) I'm on a couple medications that stopping them suddenly for even a few days has the potential to put me in the hospital if not end up being lethal depending on the severity of the withdrawal.