i didn't buy a preassembled tofu but i have the tofu hhkb and it came with a hotswap pcb, which means you can take the switches out without desoldering them. i imagine they all use the same pcb but you can probably check the bottom of the pcb. if the switch legs are soldered, you're out of luck. but if they have hotswap sockets you should be able to pop those suckers out pretty easily.
i did see a comment reply from kbdfans on the link you shared that said the switches are NOT hotswappable, however. so you might have to break out the iron.
this is what the hotswap sockets look like on the bottom of the pcb:
Show Image
(https://ae01.alicdn.com/kf/He7011ebe17d8453a9c65c3d9ec0dc2c4B/KBDfans-new-arrival-GK64-pcb-RGB-60-64KEYS-HOT-SWAP-PCB-diy-mechanical-keyboard-hotswap-socket.jpg_q50.jpg)
If you read the product page its the DZ60 soldered PCB not the hotswap version. In my opinion if you are gonna lube switches you have to desolder them. I have seen videos people injecting lubrication trough the top of the switch. Man that **** makes me cringe you are putting way to much lube in and it will be inconsistent and you don't lube all the parts so its half lubed. The pole and the hole stay unlubed for a big part. These videos are meant for people who don't really want to go into the hobby and take the easy routes for what ever reason.
If you want it consistently lubed and not overlubed with the wrong lubrication yes desoldering would be necessary. But if you don't care about the long term feeling of your keyboard you can lube like the new kids do these days injecting lube from the top.... :-\
TLDR
Desoldering and opening switches lightly lubing all the parts = Good way of lubing
Injecting lube trough the top is overlubed,Not the greatest lube, not consistently lubed = Bad way of lubing
i didn't buy a preassembled tofu but i have the tofu hhkb and it came with a hotswap pcb, which means you can take the switches out without desoldering them. i imagine they all use the same pcb but you can probably check the bottom of the pcb. if the switch legs are soldered, you're out of luck. but if they have hotswap sockets you should be able to pop those suckers out pretty easily.
i did see a comment reply from kbdfans on the link you shared that said the switches are NOT hotswappable, however. so you might have to break out the iron.
this is what the hotswap sockets look like on the bottom of the pcb:
Show Image
(https://ae01.alicdn.com/kf/He7011ebe17d8453a9c65c3d9ec0dc2c4B/KBDfans-new-arrival-GK64-pcb-RGB-60-64KEYS-HOT-SWAP-PCB-diy-mechanical-keyboard-hotswap-socket.jpg_q50.jpg)
Thanks for the in-depth response on what I may possibly expect! I'll sit tight for now and wait for the board to come!