Is this really official?
If I have legal document's of the last will of the person stating this should be given (Last will, testament, notarial act, court decisions) this should not go with " we do not support"/ " in our opinion"/ "we believe"- it should go with inheritance law.
There is nothing in Tibia rules, Tibia Service Agreement and if it goes for "Extended Tibia Service Agreement"- This is not even "sharing account" because there is only one "new" person, nor it is "account trading".
For those reasons - there should be an option of adding "Legacy contact" or option for your account being deleted if you pass away (where the last could be a troublesome for specific reasons.)