Is Harav Shteinman's tzava'ah (last will) halachically binding?

Question

The Rav Hakadosh Harav Shteinman zatzal wrote in his tzava'ah (last instructions) to the public, not to call him a Tzaddik or Yereh Shamayim, and not to write articles about him in the newspaper.

Is this halachically supposed to be followed? I'm asking because of two reasons that may apply:

• I think I've heard that the words of a person that is niftar is (sometimes?) halachically binding.
• He was a Posek, so maybe this has the status of a Psak (halachic ruling).
• (Maybe a third thing, is it Veahavta Lere'echa Kamocha-Love your fellow Jew, to do his will?)

Answer 1

R Chaim Kanievski was asked that question by private people and by representatives of newspapers and magazines. He responded the family had to adhere to his instructions but not necessarily the rest of the public.

Here is how the Life in Israel blog author wrote it up

Rav Chaim Kanievsky replied that Rav Shteinman had written his will with tremendous humility and his family must adhere to his instructions. However, the rest of "klal yisrael" is obligated to show him the honor and respect due to the gadol hador (generation's leader) and everyone is obligated in his honor. We must increase the honor of Torah and having such events and articles will increase the honor and increase "kvod shamayim". Rav Shteinman now will be very pleased with every bit of praise said about him.

The debate seems to be is it considered honoring him by fulfilling his wishes and refraining from eulogies and articles, for example, or is it honoring him by ignoring his instructions and talking about his greatness in eulogies and articles? Rav Kanievsky paskened that the family is obligated by his instructions but the rest of us are obligated to honor him and singing his praises is the greater honor.

For the translation of R Shteinman's will in English, see here.

For more on the simplicity of R Steinmann and to understand the background to his will, you might be interested in this hesped (eulogy).

Answer 2

Regarding him being a posek, nothing you indicated in the post implies that this was a pesak. Not everything a posek says is a pesak.

The more significant factor is listening to dying people's orders. Tashbets (II: 53) limits this to following his orders about the usage of his assets; not about anything he demands:

אין האדם בשעת מיתתו נביא ולא מלך ונשיא שיצוה החיים לקיים דבריו...ולא אמרו זה אלא כשצוה שיעשה מממונו כלום שמצוה לקיים דברו שהרי בממון שלו יכול לצוות

A dying person is not a prophet, or a king, or a minister, who commands the living to do his bidding...And they only said this when he instructed that his money should be used for something, that it is a mitsvah to fulfill his words, since he can make instructions about his money.

This seems clear from Rabbenu Tam as well (cf. Tosafot Gittin 13a).

For more sources, see here (Hebrew).