A resposta é não.
A discussão na comunidade Microsoft indica que você praticamente listou as opções: VBA, arrastar divisor e clique na divisa / Ctrl + Shift + U.
Concordo com um cartaz nesse tópico:
The formula bar does not auto-size according to the value or formula within the current cell and this behavior is by design. If it did, the screen would be constantly flashing if someone was using one of the arrow keys or Tab to move around the worksheet, reducing and expanding the displayed area of the active worksheet while conversely expanding and contracting the number of lines in the formula bar.
Também quero destacar os pensamentos de outro anunciante nesse tópico:
Did you know you can hide the ribbon? If you double click on the active tab in the ribbon, the ribbon is hidden. When you need a control, you can click on a tab and it comes back. It now behaves similarly to the old Menus in Office 2003. So with the ribbon hidden, you'll have the extra screen space available to set your formula bar to multiple rows. 3 rows will be the same hieght as the ribbon.