> This one is a re-implementation of the previous font, under a different
> license.

Oh, I see.

> Do you think I should just replace the previous one?

Yes, please replace the older package. Minor nitpick though: The new
package name font-opendyslexic without the second hyphen seems more in
line with the upstream name. So, perhaps you should deprecate the old
package in favor of this new one.