If they are fixed hybrids (which they look likely), as you said,...

If they are fixed hybrids (which they look likely), as you said, 2 options in 7 years time is:

1. pay out the note or
2. convert into shares

the hybrids' cost is $1B + interest capitalized. it does not move up or down. It is fixed.

If the CNP price goes up, CNP can issue less shares to obtain $1B from shareholders or capital raising & repay the principal + interest on the hybrid. So it is cheaper for CNP & better for shareholders if sp goes up - less share issued = less dilution.

my take is, the C/N can only be converted in 7 years time. not before or after. If SP is good, no conversion will take place. GR stated that it allows time to seek a suitable recapitalization structure - this is what he is referring to.

I have read the announcement about 10 times and I actually think it is well worded. The exception is, they have done a POOR job of selling the benefits.