The main reason for the battery disconnect is to remove parasitic loads. This can be stuff that's "always on" like the CO detector and possibly the fridge, as well as for errors like mistakenly leaving an inside light or the radio on.
Landing gear isn't normally an issue because they normally have a switch that you can't "leave on." Same with slides and jacks. Also with the brake switch.
1988 Coleman Sequoia - popup (1987-2007)
2012 Roo19 - hybid (2012-2015)
2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10