Lansing Township is so eroded, I'm surprised it even exists at all anymore (a lot like where I live, in Kalamazoo Township). But the municipality took steps some years ago to prevent this very thing from happening by becoming a Charter Township, which affords some additional protections. Though annexation is still possible, I don't know the detailed nuances of how that all works and who all gets to vote on it.
This is an old article from 2017 -
The portion in question to be annexed is the northeast area -
Any idea why the township is in such terrible debt?
EDIT: did some quick googling. It looks like a lot of it is from commercial real estate investments that went south, specifically,
"The estate of developer Michael Eyde is suing Lansing Township for $13.8 million for unpaid debts related to The Heights at Eastwood." (pictured above)
What a weird thing for such a lightly populated township to go "all-in" on. The loss of automotive jobs from the region seems to also have been a factor. The sad thing is, the debt ultimately falls back on the taxpayers of the Township. And if some leave, it makes it even worse for those left behind -
This will be an interesting thing to follow to see where it goes. Like you said, municipal annexation is not a very common occurrence in Michigan these days.