My observations for the northeast/east side:
I don't think there's too much gerrymandering over what's already done as there were already few SMCs for WP to focus on. Specifically, the whole movements in the East was a merry-go-round resulting from the need to split up Pasir Ris Punggol:
- It was quite obvious that Pasir-Ris Punggol would likely get split- it was one of the largest GRCs and should have had 6 MPs in fact- and Punggol and Pasir Ris are very different towns. Its perfectly logical to have a GRC for Punggol (which WP already expected and was walking the ground) By splitting it into two, there was insufficient voters for Pasir Ris (87k) and this had to be combined with some of neighbouring East Coast to bring it up to enough numbers. Pasir Ris will probably be contested by the SDA, while Punggol will be likely contested by the WP and is similar in profile to Sengkang- a sleeper pickup if the chips all fall right.
- East Coast was already underpopulated (smaller than Sengkang in fact) and had to take in voters from somewhere. Tampines is already well drawn but somewhat overpopulated, and the EBRC choose to carve out a SMC in a safe portion of Tampines instead (mostly mature HDB blocks), and to bring voters over from Marine Parade to East Coast. Joo Chiat will make it too vulnerable (see 2011) so Chai Chee had to be brought over to balance it out. It overall probably is a wash for risk profile, and WP will make another attempt which might well fall short yet again.
- But that has the effect of Marine Parade being underpopulated, and thus they have to dig for voters from the neighboring const to bring it up to numbers- EBRC choose to slice off parts of Mountbatten/Potong Pasir. Marine Parade is now dependent on Macpherson and TPL, its probably slightly less risky than EC and will also be hotly contested by the WP.
- The Aljunied change- its logical and perfectly defensible- those condos could have been overlooked but with new BTOs coming up there, they should be in Tampines as they identify more with Tampines than the far-away Aljunied. Likely wil make little to no change in the Aljunied and Tampines risk- its only 3800 votes from 2 condos at present.
- AMK was over populated and had to cough up a SMC somewhere- the choice was either on the west side (which already has Kebun Baru and YCK split up, another SMC split will result in it becoming "Hougang GRC" instead of AMK GRC), or on the east. Anything in Hougang is too risky- WP is strong in the area- so the only choice is what is Jalan Kayu (its bascially the old Sengkang West SMC from 2011/2015. Regardless, Jalan Kayu is prime territory and its going to be hotly contested by the WP as a potential pickup- all opposition knows it which is why so many are already staking claims.
- Bishan-Toa Payoh, Nee Soon and Marymount are already well drawn and match their respective estates, no justification to redraw- the only puzzling thing is why Marymount didnt get subsumed back into Bishan-Toa Payoh- they must be confident that Gan Siow Huang can hold it for the PAP. Dont think any will be contested by WP and none are at risk other than Marymount if PSP gives it a good go again.