I think it is the part about "Open during trout, salmon or steelhead seasons', which for the Willy zone says "Streams: Open May 22 - Oct 31 unless noted under Exceptions."
The exceptions for the Tualatin then say "Open all year for trout. Harvest allowed May 22 - Oct 31, 2 per day, 8 inch minimum length, remainder of year catch-and-release."
Now, honestly, I don't know if ALL the regulations around Trout in the exceptions apply to Bass, For instance, if one were to say the "harvest allowed" applied to Bass as well as Trout, then why wouldn't "8 inch minimum" also apply ?
However, I would interpret the regs to mean bass was C&R through 5/21, retention begins 5/22. But there is ambiguity in the way the regs are worded, which is why I tell people the OR fishing regs are like doing your taxes. Careful reading is required and even then it isn't always as clear as it should be.
IMO there is little point to telling someone to read the regs, without going on to say what you think they say. Strikes me as passive-aggressive. I don't get it. Don't make us guess - tell us what you men to say, or just don't say it.