Long Rest does not mean sleep. It means light activity. Reading, memorizing spells, etc., all occur over that 8 hours. This is realistic and 5e rules.
The point of 2 Long Rests per day is that right now it makes even less sense to Long Rest because it is only 1 per day. I only adventure maybe 1 hour at a time at best and Long Rest meaning End Day. So adventure 1 hour, rest 23? Makes no sense when you are supposed to be racing against time before gobbos attack, etc.
At least with 2 Long Rests per day it is adventure 1 hour, rest 8, adventure 1 hour and rest 8. That's 18 hours. Add 2 short rests per Long. Each short rest is 1 hour. That's roughly 4 more,hours for a total of 22 hours per day. This gives you roughly 2 extra hours per day that could be simply accounted for by saying some rests were longer than others, or you could maybe adventure more than an hour before each Long Rest. Either way, more believable.
It seriously means sleep for a normal human. What do you think happens in a normal day for people in d&d?
Long Rest = Exended Rest in 4e. 4e page 263 PHB, duration = at least 6 hours, Once Per Day = after finish extended rest, you have to wait 12 hours. No Strenuous Activity =
You normally sleep during an extended rest though you don't have to (some races don't sleep) light activity, regain hp spells so on.
short rests are 5 min. not going into that.
There is no time in the game currently, the voice dialog that pops isn't fully featured. This time you are making up is just that, you making it up. There is no need for additional rests, you are trying to give feedback to half a feature EA. In what way does the sleep time even remotely seem finished?
Edit* I'll do one better 5e page 70 copy/paste from freebe pdf
Long Rest
A long rest is a period of extended downtime, at least 8
hours long, during which a character sleeps for at least
6 hours and performs no more than 2 hours of light activity,
such as reading, talking, eating, or standing watch.
If the rest is interrupted by a period of strenuous activity—at
least 1 hour of walking, fighting, casting spells, or
similar adventuring activity—the characters must begin
the rest again to gain any benefit from it.
At the end of a long rest, a character regains all lost
hit points. The character also regains spent Hit Dice, up
to a number of dice equal to half of the character’s total
number of them (minimum of one die). For example, if a
character has eight Hit Dice, he or she can regain four
spent Hit Dice upon finishing a long rest.
A character can’t benefit from more than one long rest
in a 24-hour period, and a character must have at least
1 hit point at the start of the rest to gain its benefits.