I have added some edits to the Wiki as a few carriers have added tiers, changed requirements and enhanced benefits:

American:

This is the only positive. 4MM and 5MM receive Lifetime Plat Pro and Exec Plat (OWE status). This is great for those who reached those numbers before 2011 when AA counted everything earned.

https://onemileatatime.com/news/amer...miler-program/

United:

A Million Miler must choose between inheriting status from someone or using the privilege to give status. Example scenario: Bob is a 3MM who also earned Global Services, his wife Mary is 2MM (Lifetime Plat). Bob has shared the GS status with his wife, who then would've been able to pass on GS to their son. Mary must now choose whether she shares her Plat status, or gets GS from her husband.

https://onemileatatime.com/news/unit...on_eligibility

Also, let's say a 1MM earns status higher than Premier Gold. Under the old system, the companion would've received the highest status from the 1MM. Now, the companion will only receive Premier Gold regardless what 1MM has qualified for.

https://onemileatatime.com/news/unit...anion-benefit/

British Airways and Iberia:

As you may have heard, BAEC and IB+ went spend based. Lifetime Gold now requires £550K spend, while GGLfL requires a whopping £1.5M spend.

IB Infinita and Infinita Prime require €400K and €640K respectively.

https://www.britishairways.com/conte...-club#lifetime

https://www.iberia.com/us/news-updat...ria-plus-2025/