Interstate-Guide.com describes the full length of the freeway until its end with Schuster Parkway, though I have evidence that the Interstate officially ends a few blocks before this, even with the gore point to the A and 9th Street entrance ramp. See Interchange Viewer Diagram.
Based on this document, I think it's safe to say that Google Maps is wrong, and that the 705 does indeed end even with the 9th St on-ramp. This was a point of contention in a previous thread (I thought I-705 ended at Stadium, but
others indicated this to be false), but no one brought up any evidence to conclusively show the 705 ending prior to Stadium Way. This is the first true evidence I've seen that proves I-705 ends earlier than expected.
As for field evidence...
In the last year or so, WSDOT removed the only "FREEWAY ENTRANCE" sign from the Stadium Way on-ramp, but one does remain on the "on-ramp" at the southbound Schuster Parkway/Pacific Ave split. So perhaps WSDOT is catching on to that first stretch not being part of the interstate (never mind official documents already showing this to be the case). The 60 mph speed limit signs and reassurance shield don't appear until after the 9th St on-ramp, so I guess there's been some hints all along. The drop to 40 just after the Murray Morgan Bridge should have been an indicator, but WSDOT does occasionally drop limits prior to freeway endings (512 WB at I-5, 101 "EB" at I-5) so I didn't consider this to be conclusive evidence. The other giveaway that WSDOT doesn't maintain the roadway after 9th is that a small resurfacing project a year ago ended right at the gore point, and historically, that gore area used to be where Tacoma's markings (narrower lane markings than WSDOT standard) gave way to Bott's Dots, the 705's standard lane marker (until recently).