Stick to how law defines the terms hostage, prisoner and prisoner-of-war status.
"Rule 128
1. Civilian internees must be released as soon as the reasons that necessitated internment no longer exist, but at the latest as soon as possible after the close of active hostilities. (IAC)
2. Persons deprived of their liberty in relation to a non-international armed conflict must be released as soon as the reasons for the deprivation of their liberty cease to exist. (NIAC)
The persons referred to may continue to be deprived of their liberty if penal proceedings are pending against them or if they are serving a sentence lawfully imposed."
What you personally think something sounds like isn't really relevant. Of course, the situations of circumstances that gives rise to hostage taking, prisoner and prisoner-of-war isn't normal!
That's why it's defined carefully and specifically in IHL aka LOAC.
The situation with Palestinian prisoners is not the same as that you'll be used to in Europe, for example. Hostage taking definitely isn't!
Detention can go on as described above.
IAC = International Armed Conflict.
NIAC = Non-international Armed Conflict.
As to which of these the war in Gaza falls under, a case study in ICRC on the Gaza Operation some years ago asserts the following:
"At the end of the day, classification of the armed conflict between Hamas and Israel as international or non-international in the current context is largely of theoretical concern, as many similar norms and principles govern both types of conflicts."
See Rule 128 again.
It's also permitted to arrest an individual suspected of a crime hours later, including in the middle of the night. Indeed, peacetime police forces can do this too.
I repeat once more, a hostage is not equivalent to a prisoner who's been deprived of their liberty. These two categories are also not equivalent to the prisoner-of-war status.
That's the actual point and you can't really deflect away from that.