It's up to you and makes no big difference as most libraries (except LibAddonMenu-2.0 and LibMediaProvider) are only used in this addon pChat (or another few Ayantir addons).
Edit:
The following libraries can be downloaded and installed as standalone versions with their own txt file now too, so you can remove them from pChats subfolder "libs" and from the pChat.txt file "hardcoded lines" as well:
libChat2
LibAnnyoingUpdateNotificationInGame
LibMainMenu2
I hope the authors/maintainers of LibMediaProvider will do this as well soon.
Code:
; This Add-on is not created by, affiliated with or sponsored by ZeniMax
; Media Inc. or its affiliates. The Elder Scrolls® and related logos are
; registered trademarks or trademarks of ZeniMax Media Inc. in the United
; States and/or other countries. All rights reserved.
; You can read the full terms at https://account.elderscrollsonline.com/add-on-terms
## Title: pChat
## Description: pChat overhaul the way text is displayed in the chatbox
## Version: 9.3.11.25
## Author: Ayantir, modified by DesertDwellers
## APIVersion: 100028 100029
## SavedVariables: PCHAT_OPTS
## AddOnVersion: 9031125
## DependsOn: LibAddonMenu-2.0 libChat2 LibMainMenu
## OptionalDependsOn: LibAnnyoingUpdateNotificationInGame
lib/LibMediaProvider-1.0/LibMediaProvider-1.0.lua
lib/LibCustomTitles/LibCustomTitles.lua
i18n/en.lua
i18n/$(language).lua
fonts.lua
pChat.lua
pChat.xml
copyDialog.xml
bindings.xml