I think it's an important conversation to have, so you know the wishes of your loved ones (even if there's a will it's important to talk about, I think).
However what's not okay is bragging about what you might be getting, or in any way relying on that money.
My mum had a friend who got herself into trouble a lot with money. She ended up living in a caravan because she had to give up her house, and she was relying on her mum passing away and leaving her a big house that was worth around 300k. That kind of money seems crazy to me, but this woman needed it to clear her debts and then buy a small house for herself.
Her mum was 80 when she gave up her house, and she was literally waiting for her to die (which of course could come quite quickly at the age of 80) so she could have the house.
Her mum lived in the house until she was 103. Then needed to be in a care home for just over 3 years until she died at 106. That care home ate away quite a bit of the money they got for the house as it was a nice one (she'd picked it herself, she was in 100% sound mind, just needed physical help - and of course she could pick a more expensive one with a 300k house to sell!)
So, my mum's friend didn't get enough to pay off her debts, let alone buy a house.
And you know what? Part of me is glad. Because over those TWENTY SIX years, she never once made the effort to sort her life out. She took retirement as soon as she could claim her state pension, when anyone else would surely work a couple more years if they were in loads of debt.
So THAT kind of thing is disgusting.