No, not true, I'm afraid. It was only Pound who gave the nickname "Old Possum" to Eliot. 
My search brought me to this link to Michael North. 

https://books.google.com/books?id=urxqG-ibZQ4C&pg=PA77&lpg=PA77&dq20#v=onepage&q&f=false

CR

On Saturday, October 10, 2015, Chanan Mittal <[log in to unmask]> wrote:
Here's an interesting page. I love the picture of Ezra Pound surrounded by his cats. Was Eliot's poem inspired by Pound's love of cats? And was Pound nicknamed "Old Possum"? That's what the page claims. There's also a picture of TS Eliot and a cat. 

http://www.thegreatcat.org/cats-20th-century-cats-literature-t-s-eliots-cats/  

CR

On Friday, October 9, 2015, Chanan Mittal <[log in to unmask]');" target="_blank">[log in to unmask]> wrote:
PROJECT MUSE 

The article here is inaccessible but the opening page gives an inkling of its reading.

---

The Sane, the Mad, the Good, the Bad: T. S. Eliot's Old Possum's Book of Practical Cats
Marion C. Hodge
From: Children's Literature 
Volume 7, 1978 
pp. 129-146 | 10.1353/chl.0.0381

https://muse.jhu.edu/journals/chl/summary/v007/7.hodge.html

---

CR

On Friday, October 9, 2015, Chanan Mittal <[log in to unmask]> wrote:
Well, here's another take that underscores the hidden metaphysic.

T. S. Eliot and his Jellicle Cats
Levi Asher • June 24th, 2010

http://www.litkicks.com/EliotCats 

CR

On Friday, October 9, 2015, P <[log in to unmask]> wrote:
That's just the cat 😻 lover's version. They just read the lines. I want the spaces between. The dark matters. The purring.
😻
P

On 9 Oct 2015 5:13 am, Chanan Mittal <[log in to unmask]> wrote:
>
> Enjoy the rhythms.
>
> Check out this video on YouTube:
>
> http://youtu.be/XgyRzIm7U1g
>
> CR
>
> On Thursday, October 8, 2015, P <[log in to unmask]> wrote:
>>
>> I will begin by sticking in my thumb (👍) to pull out a plumb,  or something dumb.
>>
>> There is a shadowy hierarchy among the cats which ranges from the most concrete to the most mysterious. Do I detect a kind of anti-metaphysic?
>>
>> On 8 Oct 2015 8:19 pm, P <[log in to unmask]> wrote:
>>>
>>> Thank you muchly,  CR.
>>> P
>>>
>>> On 8 Oct 2015 8:06 pm, Chanan Mittal <[log in to unmask]> wrote:
>>>>
>>>> You may go to the following link and then download a PDF file.
>>>> It takes a couple seconds.
>>>>
>>>> http://www.inflibnet.ac.in/ojs/index.php/Margins/article/view/2257/1857 
>>>>
>>>> CR
>>>>
>>>> On Thursday, October 8, 2015, P <[log in to unmask]> wrote:
>>>>>
>>>>> Resulted in 'this page doesn't exist.'
>>>>> P.
>>>>>
>>>>> On 8 Oct 2015 12:33 pm, "Rickard A. Parker" <[log in to unmask]> wrote:
>>>>> >
>>>>> > I haven't had a chance to read this yet and I've got to go out but I did have have enough time to find this article that appears worth reading:
>>>>> >
>>>>> > San Jose State University
>>>>> > Department of English and Comparative Literature
>>>>> >
>>>>> > Eliot's Cats: Serious Play Behind the Playful Seriousness
>>>>> > Paul Douglass
>>>>> >
>>>>> > Recommended Citation:
>>>>> > Paul Douglass. "Eliot's Cats: Serious Play Behind the Playful Seriousness" Children's Literature 11 (1983): 109-24.
>>>>> >
>>>>> > This article is brought to you for free and open access by the English and Comparative Literature, Department of at SJSU ScholarWorks. It has been accepted for inclusion in Faculty Publications by an authorized administrator of SJSU ScholarWorks.
>>>>> >
>>>>> >
>>>>> > I created a tiny URL for the pdf document (but it is a bit slow in loading).
>>>>> > "Eliot's Cats" is available online at:
>>>>> >    http://tinyurl.com/p47ewqt
>>>>> >
>>>>> > -----------
>>>>> >
>>>>> > TinyURL was created!
>>>>> >
>>>>> > The following URL:
>>>>> >    http://scholarworks.sjsu.edu/cgi/viewcontent.cgi?article=1007&context=eng_complit_pub&sei-redir=1&referer=http%3A%2F%2Fwww.google.com%2Fsearch%3Fq%3D%2522t.s.%2Beliot%2522%2Bpekes%2Bunpublished%26hl%3Den%26biw%3D%26bih%3D%26gbv%3D2%26oq%3D%2522t.s.%2Beliot%2522%2Bpekes%2Bunpublished%26gs_l%3Dheirloom-serp.3...115397.119821.0.120261.12.1.0.11.0.0.112.112.0j1.1.0....0...1ac.1.34.heirloom-serp..12.0.0.oz4LpypK9X4#search=%22t.s.%20eliot%20pekes%20unpublished%22
>>>>> >
>>>>> > has a length of 461 characters and resulted in the following TinyURL which has a length of 26 characters:
>>>>> >    http://tinyurl.com/p47ewqt