This is what the Tenants Union website says:
New eviction rules came into effect on 19 May 2025. ‘No grounds’ evictions are now unlawful. The landlord must have a valid legal reason with evidence, to evict you. This applies to all residential tenancy agreements – both fixed-term and periodic (ongoing) agreements. See our fully updated Factsheet: Eviction – landlord ends tenancy.
I would extrapolate from that, in the absence of a reason for not renewing a fixed-term lease, you would still have the opportunity to sign another lease at a higher rent, bearing in mind that you can only raise the rent once per year. You would still have to give the appropriate notice if you were planning not to renew and had a valid reason for doing so.