Welcome to Vodafone Community
Typically a phone is supported for around 2 years in regards to firmware.
IF a phone was supplied by Vodafone ie branded then they'll not let Samsung roll out the firmware until they know it wont clash with the phone and their apps already on it.
Once Vodafone give the go ahead then the firmware is rolled out dependant on serial and build number and date of manufacture.
Vodafone nor Samsung will comment on firmware update timescales.
Current Phone > Samsung Note 20 Ultra 5G - SM9860 Snapdragon.
Samsung One Ui 2.5 / Android 10.