With introduction of long term capital gains tax on equity mutual funds, this feature has been withdrawn because the cost of switching portfolios is not justified by the additional return.
Instead we have introduced "Tax efficient Withdrawal" which helps you minimise the cost of taxes on your withdrawals.
We recommend you rebalance three times a year so that you move into the recommended funds sooner rather than later. We will remind you by email to rebalance in January, April and August. Ideally we would remind you in October too but since we do our annual portfolio review in December it makes more sense to wait until January to rebalance to the latest portfolio. We try to strike a balance. However, you are not limited to three times a year. You can always rebalance at any time as long as there are eligible long term investments at that point in time.