They won't it's best not to be hopeful at all. However you can flash Android 10 from custom built ROMs from XDA. It's super easy to do and the community is very helpful if you have trouble. lineage OS is what it will be and it can use all the Android features and Android apps. There is alot of stable builds on there.
Not sure if you want to hear this, but our authorities repair center which does Samsung repairs work inform me that they can load updates on my Note 8 for a fee of about $30 but no guarantee that it hold, meaning they will try and maybe get it loaded, and your phone might reboot a few days later and reject the softwares or patches and go backwards to whatever was pervious on the phone, it worth a try, myself thinking about it, but my Note-8 right now is a backup devices like my Note-4 collection dusk waiting for me to call either one back into service.