Almost all of the controls in an aircraft can have fatal consequences if moved incorrectly. To put an oral announcement on each of them would result in a continuous series of alarms going off.
"Can" vs "Will" is a big delineation, feathering both props at low altitude unexpectedly will result in fatalities, unless the pilots are very quick to deal with it. Almost all the other small items will sound a warning similar to what feathering a prop will sound like, ie a simple caution for the AC gens and other ancillaries to drop off line. If I switch off a bleed it will sound the same warning that feathering a prop will. Which is more important? the bleed might result in loss of cabin pressure, but if it happened to drag the cabin altitude above 10,000 feet you will then get a hard warning, so no real danger until that happens at which point you will get an elevated warning something is wrong. If not an aural warning a master warning chime at least if the prop RPM drops below a certain threshold in flight, you will already get master warnings if you shut an engine down so it's not adding to normal cockpit workload, btw this is not just an ATR problem, most turboprops will not sound much when a propeller is simply feathered, but gas generator still running. The ATR issue seems more that the condition lever and flap lever positions are not dissimilar enough and positioned right next to each other at normal operating settings. Older turboprops you would confirm propellers in max/full position for landing, which means they are full forward whilst flaps moving downwards. I also find it worrying that they moved away from the 'ridged' prop lever, probably as marketing to make it more 'jet' like, or some other stupid non ergonomic reasoning. I also think L/R is very bad terminology for engines, 1/2 better. A lot if not most of these aircraft are flown by english second or worse language crews. And refering the 1 as captains side vs 2 FO side to avoid confusion when talking with crew facing the other way. *PS ATR is engine 1&2 I just added that as my take on the L&R statements earlier.
To add to the issue, most pilots will probably note a 'caution' alert as not critical, especially on base/final. So look up, meh its an AC gen tripped, keep going we'll deal with after landing, nothing that affects landing performance, type response. Would you immediately tie it to a feathered prop?, probably not, unless you really had a point of view from the 'what's the worst it could be' angle. On the flip side a master 'Warning' in a similar position will get your attention very fast, especially if there are enunciated lights saying props are feathered.