This happened between
2008 and
2011. It seems to have happened only east of Wilson:
257 -> 258
266 -> 267
269 -> 270
270 -> 271
272A -> 273A
272B -> 273B
275 -> 276
Points on US 14 and US 61 also need to be renamed.
This is a problem for anyone who has MN I-90 270, MN US14 I-90(270), or MN US61 I-90(270) in their list. Otherwise there are no issues with using alt names.