I used to write wills for a living. It's not compulsory to include addresses in a will but it's certainly 'standard procedure'. A change of address won't invalidate the bequest but it obviously makes sense to help your executors to locate the beneficiary.
For example, my own will (which was drawn up several years ago) still refers to beneficiaries as (for example) "Frederick Herbert Jones of 46 Acacia Crescent, Frogstown in the County of Somerset" even though I know that Fred Jones moved house several years ago. I've simply inserted an additional sheet of paper into the envelope that holds my will with the relevant information. It clearly states "This sheet does not form part of my will but the information below is provided to assist my executors to locate the beneficiaries thereof". (That's particularly important in some cases, as there's one beneficiary that I've not seen for over 35 years and even I'm not too sure where he currently lives!).