Nope. itanic eliminated PA-RISC and Alpha, because both those architectures were owned by HP, and HP wanted to work with intel to make the itanic and replace those older architectures, and that's exactly what happened. Alpha was canned immediately after HP bought out the remnants of DEC in Compaq, and moved all the Alpha engineers to HP and Intel to work on itanic. (Remember, itanic was a joint venture between HP and Intel.) PA-RISC was eliminated sometime later after itanic got good enough to do so. Price/performance was not that much of a factor here; HP management wanted to move to itanic for various pie-in-the-sky reasons, and they couldn't simply backtrack and dump the itanic after pouring so much money into its development, since that would make HP management look stupid.
MIPS was indeed wiped out by x86-64.
That may have been HP's motivation, but the market did not care and Itanium did not displace non-x86* servers, rather the availability of commodity hardware with ECC RAM and other 'server' type options. It's really a give and take of hardware getting a bit better, vendors offering server solutions on that improving hardware, and hardware vendors upping the ante again etc etc.
In other words, had Itanium never been drempt up, the server market would look basically like it does today but with HP dropping support for HPPA right now instead of Itanium. Actually, the environment might look much different in that Oracle may have never purchased sun because sparc may have survived(as in maintained market share) having that little itanium slice of the market and butterfly effect that out to MariaDB not existing and java being less controversial.
MIPS really killed itself IMHO. x86 certainly kavorkianed it along, but nothing came out of the MIPS architecture to compete in a timely manner. MIPS is actually quite good, but like Alpha it had the wrong gameplan. Alpha was a trendsetter and Alpha boxes were amazing (formerly admin of a cluster of ES45 machines, Digital Unix) but digital/compaq got bought by HP and lost the war.
Not to say that x86 actually won though, the only thing x86 about and x86 CPU is that it happens to have some x86 decoders on effectively RISC core(s), so in the end RISC wins and gets no credit. MIPS (a RISC) owns the embedded router market today, ARM owns mobile, and x86 is very RISCy. Heck, the 'R' in arm used to mean RISC (still applies but the name is now just 'ARM')