It is unlikely that you could anticipate that additional value would be received by leaving now. For one, any surplus existing might be missed out on where this is distributed to members.
In addition, the basis used to calculate transfer values will increase on 1 May so the minimum amount payable will increase. Getting this amount is subject to the scheme being appropriately funded, but Motorola may not wish to walk away from unfunded pension liabilities from a PR / HR perspective.
It should be possible to identify the scheme funding positoin from the most recent Scheme Report and Accounts / valuation report?