So I think they will if you optioned finance in the buying journey, the reason I say this is a bought a GRY in May 21 and its due delivery in Aug 22, the 0% finance deal remains as I signed a contract effectively at the time of purchase therefore Toyota seem to be honouring the agreement at time of sale.
I also asked having opted for cash whether they'd honour the current finance rate as I'd like to switch to finance - she said they could move me to finance now but means doing a hard credit check so was going to ask TGB finance team whether they'd keep the current offer for those who bought when they did but not taking delivery for a year. Its unprecedented at Toyota to have such large lead times (excluding the GRY), so its not a common problem to deal with, she did say she'd get back to me and when she does I'll post on here.