WPEngine can likely show there hasn't been a material change in their marketing dress since that investment was made that would constitute active confusion on their behalf.
I’m imagining they weren’t calling themselves "The most trusted WordPress platform" and "The Most Trusted WordPress Tech Company" 13 years ago. 'Trusted' can be read with the meaning 'seen as trustworthy' rather than the meaning 'utilized' which could be found to be creating confusion.