>>535160709
>>535160894
Official website got updated recently. It's the current version of the new official timeline: https://sonic.sega.jp/sonic.sega.jp/SonicChannel/character/worldstory/
Basically most games are in initial release orider (no surprise there) except CD is before 2 and Heroes and Shadow which are before Battle.
The games that are absent are said to be added later after the "lore team" reviews with Sega if their spots/stories need any retcons.