The 3ZZ-FE they were offering back then in SE Saloon was non-VVT-i, whereas if they decide to offer it now, it will be VVT-i. They simply cannot afford to offer 1.6L 1ZR-FE, because of the following reasons:
1. It will be expensive resulting in a low profit for IMC and they might set its price very near the current price tag of 1.8L Altis, so no one will opt for 1.8L.
2. It is 124PS whereas the current 1.8L Altis is 130PS. This depicts a slight power difference as the torque also has a minimal difference. Giving 1ZR-FE in the altis will significantly lower their sales of 1.8L Altis.