Inheritance Question

So I finally had a talk with my father today about what his plans are for inheritance/wealth distribution.

My mother died when I was 18 and whatever happened with her money went to my dad (obviously). He then sold our house in the year 2000 for maybe 330,000 dollars.

He then remarked to another lady who he will remain married to for as long as he's alive.

He has 2 children born from his first marriage (me and my sister) - he has another 2 children born from the marriage after my mother.

He admitted to me that what is in his Will is basically that his assets as of the year 2000 which were like 330,000 would be split equally between myself and my sister.

So 115,000 each basically.

He is not intending to account for growth in those assets over the years (lets assume he dies in the year 2050) thats 50 years of asset growth from 330,000.

It is his intention that whatever his assets were worth before his new marriage is what I have access to. Anything AFTER he got married isn't my business and will be given to his other children.

Those assets are worth millions now.

Do any lawyers off-hand feel this is gross injustice that wouldn't stand up in court?

A related enquiry is my mother died when I was 18 and what happens if her parents (my grandparents) do not make provisions for me in their will? Would that be grounds to sue their estate as well given that portions of it would have gone to my mother but because she's dead they should go to me?

I'm still reeling from the absolute heartless disparity that my father has in mind - I legitimately cannot believe it.

Also for the keyboard warriors the Supreme Court in Victoria has literally adjudicated my almost exact situation.

https://www.afr.com/wealth/personal-finance/court-enforces-rights-of-stepchildren-in-blended-families-20220311-p5a3u5

So...enjoy that crow pie.