Relicensing under any other license, including the LGPL, is exactly the same thing. Either the reimplementation copies protected expression, in which case it would be required to be GPL-2.0-only, or it does not, in which case we can choose the most fitting license.
If you believe that using an MIT license is not correct, then you defacto also believe that using an LGPL license is not correct.
> Relicensing under any other license, including the LGPL, is exactly the same thing. Either the reimplementation copies protected expression, in which case it would be required to be GPL-2.0-only, or it does not, in which case we can choose the most fitting license.
Using LGPL could help the argument that the project was in good faith, making it more likely to be accepted as non-derivative. Its arguable that the relicinsing would be required to make the project work as a library and so LGPL would be the best choice since that (I assume) preserves most of the terms and intention of the original license. This makes it much easier to show that the license was changed solely to allow other projects to use it as a library.
By using the MIT license its much easier to argue that the project is in bad faith (and potentially derivative), since the license change can be seen as a deliberate choice to remove the protections of the original license. Its harder to argue that the license change was only so the project can be used a library because then you would have used LGPL instead.
The OP you're referring to made a distinction between legally and morally correct. Legally, you appear superficially correct, but I'm not a lawyer, and neither was the OP. Morally, the LGPL is correct.
Judges are human and will take into account good faith and attempts to maintain the spirit of the license. Choosing the LGPL signals a desire to maintain the spirit of the license. The MIT signals bad faith. Judges don't like that.
If you believe that using an MIT license is not correct, then you defacto also believe that using an LGPL license is not correct.