Each phone comes with a specific commitment - I think it depends significantly on its components and arrangements with partners.
Now there is also a new EU law that prescribes that spare parts should be available for a long time after the end of sales, which can revolutionise the market (not sure though what is meant by critical parts as most of the phones are not repairable to FP standard)
including obligations for producers to make critical spare parts available within 5-10 working days, and for 7 years after the end of sales of the product model on the EU market
https://energy-efficient-products.ec.europa.eu/product-list/smartphones-and-tablets_en
please note this is the fellow user’s comment, not the company statement 