Nothing in that list sounds official. Almost all list is either NOT related to core OS functionality or is just Android-ifying. Also, it won't be named WP8.1.1. The next 3 updates are obviously GDR1, 2 and 3. After that, Threshold is expect, which will be WP8.2/8.5/9.0.

Lock screen applications will be built inside core system -> NO, there are APIs in WP8.1, but there won't be nothing built in.

Music controls in Action Center -> Does not make sense IMO.

Application Games to be deleted and replaced with Xbox One application -> Does not make sense.

Messages in bubbles and chat heads similar to Facebook messenger -> Lol, no. WP design is square.

Internet Explorer applications -> What?

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Tiles to update as frequently as 30 seconds if feature is turned on by user or developer -> Bullcr*p. WP8.1 already allows this. See Clock Hub.

Music volume controls to be centred -> This is NOT Android.

Photos will have description such as name, place and time -> This won't happen. It would bring too much clutter to the interface.
Not core OS functionality:

Name to be decided YouTube application to be built completely with html 5 coding as requested by Google

Instagram application to have DIRECT MESSAGING and better video uploading capabilities and camera fixes UI for camera to be tweaked with enhanced features from Nokia Camera application

KIK Messenger to be finished in late June, overhauled design and html 5 support Skype with completely new design

Facebook messenger to have improved notifications, polished design and new set of fonts along with video chat, calling and improved emoji store

Facebook application from official company

Email/Outlook application to follow same design as computer base

Store with wallpapers from featured applications -> There were applications with "wallpapers" since WP7 launched.